'Fast' in the Bible

And they said unto him, Why do the disciples of John fast often, and make prayers, and likewise the disciples of the Pharisees; but thine eat and drink?

And he said unto them, Can ye make the children of the bridechamber fast, while the bridegroom is with them?

But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days.

I fast twice in the week, I give tithes of all that I possess.