'Forty Days' in the Bible

When I had gone up into the mountain to be given the stones on which was recorded the agreement which the Lord made with you, I was on the mountain for forty days and forty nights without taking food or drinking water.

Then at the end of forty days and forty nights the Lord gave me those stones, the stones of the agreement.

And I went down on my face before the Lord, as at the first, for forty days and forty nights, without taking food or drinking water, because of all your sin, in doing evil in the eyes of the Lord and moving him to wrath.

So I went down on my face in prayer before the Lord for forty days and forty nights as I did at first; because the Lord had said that he would put an end to you.

And I was in the mountain, as at the first time, for forty days and forty nights; and again the ears of the Lord were open to my prayer, and he did not send destruction on you.