Deuteronomy 9:18-20

181I fell down before the Lord, 2as at the first, forty days and nights; 3I neither ate bread nor drank water, 4because of all your sin which you had committed in doing what was evil in the sight of the Lord to provoke Him to anger.

19For 5I was afraid of the anger and hot displeasure with which the Lord was wrathful against you in order to destroy you, 6but the Lord listened to me that time also.

20The Lord was angry enough with Aaron to destroy him; so I also prayed for Aaron at the same time.