Deuteronomy 9:18-20

18“Then I fell down before Adonai like the first time, for 40 days and 40 nights. I did not eat bread or drink water—because of all your sin that you committed, doing evil in Adonai’s sight, provoking Him to anger.

19For I was afraid of the fierce wrath and fury which Adonai bore toward you—to destroy you. But Adonai listened to me that time also.

20Adonai was angry enough with Aaron to destroy him, so I prayed for Aaron also at the same time.