'Nights' in the Bible

When I went up the mountain to receive the stone tablets, the tablets of the covenant the Lord made with you, I stayed on the mountain 40 days and 40 nights. I did not eat bread or drink water.

The Lord gave me the two stone tablets, the tablets of the covenant, at the end of the 40 days and 40 nights.

Then I fell down like the first time in the presence of the Lord for 40 days and 40 nights; I did not eat bread or drink water because of all the sin you committed, doing what was evil in the Lord’s sight and provoking Him to anger.

“I fell down in the presence of the Lord 40 days and 40 nights because the Lord had threatened to destroy you.

“I stayed on the mountain 40 days and 40 nights like the first time. The Lord also listened to me on this occasion; He agreed not to annihilate you.