A naked person is not permitted to pray with his nakedness uncovered. Therefore, one who is naked in the ritual bath and does not have time to get out, get dressed, and pray before the end of the appointed time, he may pray in the ritual bath while he is naked, as long as his sexual organ is covered by water. The scholars asked: What does it help if he puts himself into water up to his neck? Even if his eyes are out of the water, his chest and his heart are in the water, so his heart can “see” his sexual organ, as there is no separation between the heart and the sexual organ. (This is the reason Chassidim put on a gartel before prayer, to separate the heart from the sexual organ. Litvaks make do with the belt or the button which closes the trousers.)
Answer: The permission to pray while naked in the ritual bath is only when the waters are opaque and not clear. The scholars then go on to discuss a case in which the heel sees the sexual organ, such as if one wears a cloak with no undergarments — may one pray? The Talmud rules: If the heel sees the sexual organ one may pray, but if it touches the organ, one is forbidden to pray.
(Babylonian Talmud, Tractate Berachot 25b)
>b>The Talmudic text:
“If he went down to immerse himself, if he is able to come up and cover himself and recite the Shema before the rising of the sun, he should go up and cover himself and recite, but if not he should cover himself with the water and recite” (Mishnah Berachot 3:5).
Gemara: If not, he should cover himself with water and recite. But in this case his heart sees the sexual organs! Rabbi Eleazar said — or as some also say, Rabbi Acha the son of Abba the son of Acha said in the name of our teacher [Rav]: They meant this to apply to turbid water which is like solid earth, in order that his heart should not see his sexual organ. Our rabbis taught: If the water is clear, he may sit in it up to his neck and say the Shema; some say he should stir it up with his foot. On the ruling of the first Tanna, his heart sees his nakedness. He held that if his heart sees the sexual organ it is permitted. But his heel sees his nakedness. He held that if his heel sees his nakedness it is permitted. It has been stated: If his heel sees his nakedness it is permitted; if it touches, Abaye says it is forbidden and Rava says it is permitted. This is the way in which R. Zevid taught this passage. Rav Chinnena the son of Rav Ika said it thus: If it touches, all agree that it is forbidden. If it sees, Abaye says it is forbidden and Rava says it is permitted; the Torah was not given to the ministering angels. The law is that if it touches it is forbidden, but if it sees it is permitted.