As small as it seemingly is, the mitzva to wash one's hands before Birchat HaMazon is a rather complex one. There are at least three main reasons given for this practice, and much debate as to whether or not the mitzva is still binding today (it is certainly not an extremely common practice in many places). Our Chabura this week will focus mainly on understanding the mitzva itself, and will conclude with several of the halachic minutiae involved in its performance.

The gemara in Chullin 105a states that washing one's hands before eating (mayim rishonim) is a mitzva, while washing before Birchat HaMazon (mayim acharonim) is a chova (obligation - this term will be discussed in greater detail as we progress). Why are mayim acharonim considered to be obligatory? The gemara states that since the Sages advise us to eat salt with every meal, we have a fear that "Sodomite salt," which could potentially blind a person if it came in contact with his eyes, was mixed into the salt. Thus, the Sages obligated us to wash our hands after each meal so as to remove this dangerous salt.

The second source for mayim acharonim is found in Berachot 53b. There, the gemara learns the obligations of mayim rishonim, mayim acharonim, washing one's hands in oil by a meal (an ancient practice), and Birchat HaMazon from the verse of "V'hitkadishtem v'heyitem kedoshim" - and you should make them holy and you will be holy (Vayikra 20:7). Why do we need two sources? What are the varying natures of these sources and how do they affect the practice of mayim acharonim? What is the difference between mitzva and chova?

The first view that we will deal with is that of Tosafot. In both locations, they claim that the exegesis found in Berachot 53b is merely an "asmachta" - a use of a verse to back up a known law, but not a binding source for the law in and of itself. As such, they deal primarily with the reason given in Chullin 105a. According to their view, since we no longer worry about Sodomite salt, there is no need to wash mayim acharonim nowadays. Rif argues with Tosafot, although not completely. He claims that even if we no longer worry about Sodomite salt, there is yet another reason that one should wash mayim acharonim. That reason stems from a case cited in Yoma 83b where a person lost their life due to their failure to wash mayim acharonim. Since such a drastic result once came about, Rif claims that this is sufficient reason to maintain the practice.

Ran introduces a new level into this debate. He takes both sources as being of equal authority, and thus is left wondering if mayim acharonim is a chova, as per Chullin 105a, or if it is a mitzva stemming from a verse, as per Berachot 53b? His answer is that mayim acharonim is a multi-faceted obligation. If one's hands were to be dirty, he would then have a mitzva to wash them before making a bracha (similar to the requirement for priests to wash their hands before eating anything that was holy). However, even if one's hands were clean, there would still be on obligation due to the danger of Sodomite salt. Rosh has a similar approach, and he further quotes Rav Hai Gaon who claims that the mitzva is only for the one leading Birchat HaMazon (i.e. the one who will be saying the bracha - the previous practice was that one person said all of Birchat HaMazon and everyone merely listened and thus fulfilled their obligation), while all others present had to do so only because of the potential danger (this is also the view of the Meiri and Ritva). However, Rosh concludes that today we do not wash mayim acharonim, since each of the reasons given in the gemara has become void. The reason of Sodomite salt no longer applies as per the view of Tosafot, and the proof brought from the verse cited in Berachot no longer applies since we no longer wash our hands in oil, and thus this verse is no longer a binding source for any of the practices mentioned in it. Mordechai takes a different approach to the matter. He claims that since we no longer have the practice of mayim acharonim, our hands are no longer considered to be dirty in the sense that we would be unable to make a bracha. However, his initial reason for the disappearance of this practice is left unstated. Finally among the Rishonim is the view of Ramban, who adds in a new angle. He claims that the term mitzva refers to the mitzva to listen to the Sages, and thus the obligation to wash mayim acharonim still applies today.

Among the poskim there are also various approaches to mayim acharonim. Rambam adds in a small detail concerning this law. He claims that any bread that has salt in it would be enough to require one to wash mayim acharonim. The Lechem Mishna plays off of this and states that some versions of Rambam say that all salt requires mayim acharonim, and thus the obligation nowadays is due to a fear of any salt whose composition may be similar to that of Sodomite salt. On the other hand, the Tur (and the Shulchan Aruch) takes the more lenient approach of Ritva and the Meiri, claiming that the main obligation is that of the one who leads Birchat HaMazon, while mayim acharonim is optional for others at the table. In his comments on the Tur, the Beit Yoseif brings down the reason of Rif, stating that despite the present absence on Sodomite salt, there still exists an obligation due to the incident brought down in Yoma. By contrast, the Darchei Moshe claims that the accepted practice follows the view of Tosafot, and thus there is no need to wash mayim acharonim.

Finally, there is the view of the Aruch HaShulchan. He claims that even Tosafot would admit that there is an obligation to wash mayim acharonim. If this is true, why do Tosafot say that there is no longer a need to do so? He answers that Tosafot were trying to offer a defense for the people of their generation who had stopped washing mayim acharonim, and thus they presented to reason of Sodomite salt as the main reason, thus allowing for the possibility of declaring the practice no longer necessary. To back up this point, he quotes the Shut Min HaShamayim which says that one who treats this mitzva lightly will, in turn, have Hashem treat him and his life lightly.

Before we proceed, a few final notes. First, what is the difference between saying that mayim acharonim is a mitzva and saying that it is a chova? Two possible differences are offered. According to Tosafot, the difference is related to a gemara at the end of the first chapter of Eruvin. There the gemara discusses various things that one does not have to do in a situation of war. One would be free from his obligation to wash his hands before the meal while in battle, since that obligation is a mitzva and thus can be suspended under dire circumstances. However, if the reason for mayim acharonim is due to personal danger, then even in war one must continue to wash his hands to ensure that they are free of any dangerous salts. A second possibility is offered by the Darchei Moshe. He states that if one only has enough water to wash his hands once and has just completed a meal and wants to eat another one later on, he should wash mayim acharonim now and either neglect the other meal or eat it with his hands covered. Again, this stems from the fact that mayim acharonim is an obligation stemming from personal safety. Based on this, the Magen Avraham says that nowadays it is preferable that one use the water for mayim rishonim, since we no longer have Sodomite salt. By contrast, the Mishna Berura claims that if one has no water at all, he should say Birchat HaMazon, but wash his hands at the next possible time so as to remove any Sodomite salt that may be on his hands.

A second point made by Rosh, the Tur, and other poskim is that even if one does not subscribe to the view that there is an obligation to wash mayim acharonim, if a person is generally finicky with regard to personal hygiene, he has an obligation to wash his hands after eating a meal.



We will now investigate several of the particular laws concerning mayim acharonim. Keep in mind what we have discussed until now, as many of the ideas already mentioned play out in the details as well.

Is there a need to make a blessing for mayim acharonim in the same sense that one is said for mayim rishonim? According to Tosafot, since mayim acharonim is only an obligation based on safety, there is no blessing made. This view is held by Rav Amram and Rambam as well. The Bach similarly claims that even though there is a mitzva of mayim acharonim that is connected to holiness, and thus a blessing should be made, the main reason for this law relates to the filth that is on one's hands, and thus no blessing is made (note the difference between the concepts of Sodomite salt on the hands, regular filth on the hands, and holiness. The difference between the first two should by now be clear, and holiness is distinguished from them insofar as it is a mitzva that would require a blessing and not simply a matter of hygiene). The Aruch HaShulchan claims that in reality, there is a need to bless on mayim acharonim. However, in the same way that the blessing of HaMotzi covers all food eaten at the meal, so too does the blessing said on mayim rishonim cover all washings made during the meal.

(As a side point, there is a discussion as to what the text of the blessing would be if there was to be a need to make one. Ran claims that the blessing would be al netilat yadayim, as by mayim rishonim. He also cites a view (found in the commentary of Rashba) that claims that since there is no need to use a vessel to wash mayim acharonim, the blessing is al rechitzat yadayim. However, he fails to see why there is a difference between the two. Ra'avad makes an interesting split in the law. He states that if one eats something that renders his hands filthy he says al rechitzat yadayim. However, if the food is dry and leaves no residue on the hands there is no blessing.)

The gemara in Chullin goes on to list several procedural details concerning mayim acharonim, most of which are the subject of minimal, if any, debate. Unlike mayim rishonim, mayim acharonim do not require that one use a utensil to pour the water. Ritva quotes this statement and adds that they also do not require human force, meaning that one may wash mayim acharonim directly from a faucet. However, the Be'er Heitev claims that both a utensil and human force are needed for mayim acharonim, and such is the accepted practice today.

The next line in the gemara discusses the prohibition of letting the water from mayim acharonim fall onto the ground. Rosh explains that this is forbidden due to a "ruach ra'ah," or some form of evil spirit, that rests within these waters. As such, they should not be poured onto an area where people may potentially walk and thus endanger themselves. The Beit Yoseif quotes Rashba, who claims that as this is only a Rabbinic prohibition, it might be possible to be lenient with regard to it. However, Rambam is strict about this, and the Tur and the Shulchan Aruch codify it as law. The Magen Avraham adds two qualifications. First, he claims that the notion of "ruach ra'ah" applies only to a dirt floor, and thus it would be permissible to pour mayim acharonim onto a tiled surface. Second, he adds that since the problem is only that people may walk on the water, there is no prohibition of pouring the water under the table, or any such place where people do not walk.

The final point made in the gemara itself concerns the temperature of the water. Since the point of mayim acharonim is to remove the filth from the hands, the water may not be at a temperature that is so high that it actually produces the opposite effect. Were the water to reach a certain level of heat, it would actually soften the hands, allowing the filth to embed itself in them. In general, the line is drawn at the level of "yad soledet" - defined as the temperature at which a person would pull his hand out of the water, or, more precisely, the temperature at which the water would burn a baby's delicate skin.

There are a few further details that are discussed among the various Rishonim and poskim. Mordechai and Rambam raise the point that one should direct his hands downward when washing mayim acharonim. This is done so that the water, and the filth along with it, will fall right off of the hands. The Beit Yoseif raises another point. He cites the Shulchan Shel Arba, which claims that there is no measurement of water that is required for mayim acharonim. This is the accepted rule, although the Mishna Berura points out that the GR"A used to use a revi'it (appx. 3.3 ozs.) for mayim acharonim. As far as which waters may or may not be used, the Beit Yoseif quotes the Torat HaBayit which claims that since the purpose of mayim acharonim is to remove the filth from the hands, any liquid that will accomplish this task suffices, even those waters that are not fit to be used for mayim rishonim (e.g. waters that are murky). He further mentions the fact that unlike mayim rishonim, where one must immerse the entire hand, one need only wash his hands until the second knuckle, since that is generally how far up the hand we expect any residue from the food to reach. Finally, the Beit Yoseif mentions the concept that one must say Birchat HaMazon immediately after washing. The Aruch HaShulchan states in this regard that while one may no longer eat once they have washed, it is permissible to talk before Birchat HaMazon (although one should still try to begin Birchat HaMazon as soon as possible).

Two final issues before we conclude. The first is whether or not drying one's hands is part of the mitzva of mayim acharonim. According to Rambam such a component of the mitzva does exist, while Rashba claims that it does not. The Derisha explains that the reason for not drying one's hands is that we are only strict about drying when one is about to eat, but not in our case where the eating has concluded. Finally, the Magen Avraham cites the Yam Shel Shlomo who claims that only the one who is leading Birchat HaMazon has a requirement to dry his hands (see above as to the significance of leading Birchat HaMazon).

And finally, a little known procedural fact. The Tur writes that when there are five or fewer people present at a meal, the greatest person present, who presumably will be the one asked to lead Birchat HaMazon, washes first. This way, he has a few moments to look over the text of Birchat HaMazon while his friends wash. If there are more than five people, the washing begins with the least important individual and goes around the table until the greatest five people present are the only ones remaining. At that point, the procedure is the same as if there were only five.

Just as an afterthought, I have seen several places where although people wash mayim acharonim, the women do not do so. I found absolutely no source anywhere for such a distinction, and none of the reasons given for the mitzva of mayim acharonim seem to lend themselves to such a practice.

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