Deuteronomy 9:18-20

18Then I again fell down with my face on the ground, to pray to the Lord. I did that for 40 days and nights. I did not eat or drink anything. You had done an evil thing which caused the Lord to be very angry.

19I prayed, because the Lord had said that he would destroy you. He was so angry with you that I was very afraid. But the Lord listened to me this time too.

20The Lord was also angry with my brother Aaron. He wanted to kill Aaron. But at that time, I prayed for Aaron too.