Deuteronomy 9:9, 18

When I went up the mountain to receive the tablets of stone, the tablets of the covenant that the LORD made with you, I remained on the mountain forty days and forty nights. I neither ate bread nor drank water.

Then I lay prostrate before the LORD as before, forty days and forty nights. I neither ate bread nor drank water, because of all the sin that you had committed, in doing what was evil in the sight of the LORD to provoke him to anger.