Why Israel Fasts Monday and Thursday and Sodom Fell

(Gen. 19:24:) "AND THE LORD RAINED DOWN UPON SODOM," etc. Let our master teach us: A court that decreed a fast upon the community so that rains would come down, and the rains came down on that very day — is it correct that they should complete it? Thus did our masters teach: If they were fasting and the rains came down before the rising of the sun, they do not complete it; after the rising of the sun, they complete it — the words of R. Meir. But R. Judah says: before noon they do not complete it; after noon they complete it. And from where did the generations find support that they should fast on the second day (Monday) and on the fifth day (Thursday)? Rather, when Israel did that deed (of the golden calf), Moses went up on a fifth day and came down on a second day. From where? R. Levi said: He went up on a fifth day. And from a fifth day to a fifth day to a fifth day — that is fifteen; and from a Sabbath eve to a Sabbath eve to a Sabbath eve — fifteen — that is thirty; and from a Sabbath to a Sabbath — eight — that is thirty-eight; and a first day of the week and a second day of the week — that is forty. Therefore the Sages ordained that they should fast on the second day and on the fifth day, on the ascent of Moses and on his descent. And at the end of forty days they fasted and were weeping before Moses, and the Holy One, blessed be He, was filled with mercy upon them, and He made that day for them a day of atonement for their iniquities, and this is the Day of Atonement, as it is said (Lev. 16:30): "For on this day He shall atone for you, to cleanse you." See how lovely is repentance! The Holy One, blessed be He, said (Mal. 3:7): "Return to Me, and I will return to you." For if a person has several iniquities in his hand, and he repents before the Holy One, blessed be He, He reckons it for him as though he had not sinned, as it is said (Ezek. 18:22): "All [his transgressions] that he committed," etc. And since the Holy One, blessed be He, warns him a first time, and a second, and a third, and he does not repent, He exacts punishment from him, as it is said (Job 33:29): "Behold, God works all these things," etc. Since He finds no benefit from him, immediately He exacts punishment from him. Know for yourself that it is so: when the Holy One, blessed be He, sought to overturn Sodom and her companions, Abraham stood and sought mercy for them, thinking that perhaps there was hope, as it is said (Gen. 18:23): "And Abraham drew near and said," etc. What is "and he drew near"? R. Joshua says: "drawing near" is nothing but an expression of war, as it is said (2 Sam. 10:13): "And Joab and the people who were with him drew near to the battle." R. Nehemiah says: "drawing near" is nothing but an expression of prayer, as it is said (1 Kings 18:36): "And it came to pass at the offering up of the evening offering, that Elijah the prophet drew near," etc. And the Sages say: "drawing near" is nothing but an expression of request, as it is said (Gen. 44:18): "Then Judah drew near to him." Abraham said before the Holy One, blessed be He (Gen. 18:25): "Far be it from You," etc. And he was seeking mercy for them until he went down from fifty to ten. Since he found no merit for them, the Shekhinah departed from him, as it is said (Gen. 18:33): "And the LORD went away when He had finished," etc. Immediately the punishment came upon them. [From where is it shown? From what we have read on the matter (Gen. 19:24):] "AND THE LORD RAINED DOWN UPON SODOM."