'Fast' in the Bible

"Speak to all the people and priests of the land as follows: 'When you fasted and lamented in the fifth and seventh months through all these seventy years, did you truly fast for me -- for me, indeed?

"The Lord who rules over all says, 'The fast of the fourth, fifth, seventh, and tenth months will become joyful and happy, pleasant feasts for the house of Judah, so love truth and peace.'