'Nights' in the Bible

When I was gone up onto the mountain to receive the tables of stone, even the tables of the covenant which Yahweh made with you, then I stayed on the mountain forty days and forty nights; I did neither eat bread nor drink water.

It came to pass at the end of forty days and forty nights, that Yahweh gave me the two tables of stone, even the tables of the covenant.

I fell down before Yahweh, as at the first, forty days and forty nights; I did neither eat bread nor drink water; because of all your sin which you sinned, in doing that which was evil in the sight of Yahweh, to provoke him to anger.

So I fell down before Yahweh the forty days and forty nights that I fell down, because Yahweh had said he would destroy you.

I stayed on the mountain, as at the first time, forty days and forty nights: and Yahweh listened to me that time also; Yahweh would not destroy you.