Deuteronomy 9:18-19

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.