Shulchan Aruch, Orach Chayim 77 — שולחן ערוך, אורח חיים עז

Saying holy words facing urine, and how much water is poured into it so that one may say them.

seif 1 The Mechaber writes that one may not read holy words facing urine until a revi'it (a measure of liquid) of water has been added to the urine. After that, reading facing it is allowed. The Aruch HaShulchan names Kriyat Shema, Tefillah and brachot. The Mishnah Berurah adds that "facing" here carries all the rules of distance that apply to excrement in siman 79.

The Mishnah Berurah explains the reason for the leniency. By the Torah, reading is forbidden only facing the stream itself, while a person is urinating. Once the urine has fallen to the ground, the prohibition is only rabbinic, so the Chachamim allowed a revi'it of water to cancel it, even when there is a lot of urine. The Aruch HaShulchan explains that the rabbinic prohibition applies while the urine is tofe'ach al menat lehatfiach (wet enough that something touching it becomes wet enough to wet something else). Both limit the leniency to urine that does not give off a bad smell. Where it smells, the Mishnah Berurah writes, reading facing it is a Torah prohibition, and a revi'it does not help. He writes that enough water must be added to remove the smell. The Aruch HaShulchan writes that where there is a smell, reading is forbidden in every case, even after water is added. The Mishnah Berurah cites a view that the revi'it must be poured all at once. Otherwise each small amount of water would be cancelled as it falls.

The Mechaber writes that the rule does not change whether the urine lies on the ground or sits inside a vessel (following the Tur, as the Gra notes). It is also the same whether the urine was in the vessel first and the water was added, or the water came first. The Mishnah Berurah adds a case. A revi'it of water lay on the ground first, and one urinated onto it. One may then say Kriyat Shema facing it, even if the urine has made it spread further. When the urine is on the ground, the Mishnah Berurah and the Aruch HaShulchan write that the water must reach every spot where the urine is still wet enough to wet something else. The Mechaber excludes an avit (a chamber pot set aside for urine), whose law is in siman 87. The Mishnah Berurah explains that one may not read facing such a vessel even when it holds no urine at all. Pouring water into it does not make the vessel itself acceptable.

seif 2 The Mechaber writes that one revi'it is needed for urine from one time. For two times, two revi'iot are needed, and for three times, three. The Rema adds that the count continues this way. The Magen Avraham explains that for one time, it makes no difference whether one urinated a lot or a little.

The Mishnah Berurah cites the Chacham Tzvi on urine that is less than a revi'it. In that case it is enough to pour in more water than urine. The Chacham Tzvi explains that the revi'it was set only as a leniency for a large amount, not as a stringency. The Mishnah Berurah writes that the later poskim agreed. The Aruch HaShulchan records this view and the Magen Avraham's view. He also records a further view, from the Shiltei Gibborim, that water equal in amount to the urine is enough. He adds that one may be lenient here, since the prohibition is rabbinic.

The Mishnah Berurah writes that the Mechaber's rule for two times follows the Rambam. The Rashba holds that one revi'it is enough even for several times. The Mishnah Berurah cites the Magen Gibborim, who suggests that even the Rambam requires a new revi'it only in one case. Water was already poured in, and then one urinated again. If one urinated several times before any water was added, one revi'it is enough. The Mishnah Berurah adds that the Gra agrees with this in practice. The Gra himself questions the Mechaber's rule. By that rule, one who stopped partway would need two revi'iot, while one who urinated without stopping would need only one. The Gra concludes that the Rashba's view seems primary. The Aruch HaShulchan writes that one may rely on the Rashba's view in sha'at hadechak (a time of pressing need).