'Forty Days' in the Bible

When I was gone up onto the mount to receive the tablets of stone, even the tablets of the covenant which LORD made with you, then I abode on the mount forty days and forty nights. I neither ate bread nor drank water.

And it came to pass, at the end of forty days and forty nights, that LORD gave me the two tablets of stone, even the tablets of the covenant.

And I fell down before LORD, as at the first, forty days and forty nights. I neither ate bread nor drank water, because of all your sin which ye sinned, in doing that which was evil in the sight of LORD, to provoke him to anger.

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

And I stayed on the mount as at the first time, forty days and forty nights, and LORD hearkened to me that time also: LORD would not destroy thee.