Takhrij Hadith 1522: "A barren woman came to…"

A barren woman came to Moses, and asked him to supplicate for her, so he supplicated for her, and Allah said to him: I have decreed her barren. Then after some time she came to him carrying a child, so he asked her, and she said: My son. So Moses returned and asked his Lord about that, and He said to him: Every time I decreed her barren, she said: O Most Merciful, so My mercy preceded My decree