Fasting — voluntary abstinence from food for spiritual purposes — is practiced in Scripture for repentance, mourning, seeking God's guidance, and intensified prayer; Jesus assumes His followers will fast, but warns against ostentation.
Matthew 6:16
Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.
'When thou fastest, anoint thine head'; fast in secret, and the Father shall reward openly.
Wherefore have we fasted, say they, and thou seest not? wherefore have we afflicted our soul, and thou takest no knowledge? Behold, in the day of your fast ye find pleasure, and exact all your labours.
The true fast God chooses: to loose bands of wickedness, feed the hungry, and free the oppressed.
Behold, ye fast for strife and debate, and to smite with the fist of wickedness: ye shall not fast as ye do this day, to make your voice to be heard on high.
The true fast God chooses: to loose bands of wickedness, feed the hungry, and free the oppressed.
Is it such a fast that I have chosen? a day for a man to afflict his soul? is it to bow down his head as a bulrush, and to spread sackcloth and ashes under him? wilt thou call this a fast, and an acceptable day to the LORD?
The true fast God chooses: to loose bands of wickedness, feed the hungry, and free the oppressed.
Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?
The true fast God chooses: to loose bands of wickedness, feed the hungry, and free the oppressed.
Is it not to deal thy bread to the hungry, and that thou bring the poor that are cast out to thy house? when thou seest the naked, that thou cover him; and that thou hide not thyself from thine own flesh?
The true fast God chooses: to loose bands of wickedness, feed the hungry, and free the oppressed.
And Jesus said unto them, Can the children of the bridechamber mourn, as long as the bridegroom is with them? but the days will come, when the bridegroom shall be taken from them, and then shall they fast.
Jesus' disciples will fast when the bridegroom is taken away.
Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise; and so will I go in unto the king, which is not according to the law: and if I perish, I perish.
Esther calls a three-day fast before approaching the king.
And he caused it to be proclaimed and published through Nineveh by the decree of the king and his nobles, saying, Let neither man nor beast, herd nor flock, taste any thing: let them not feed, nor drink water:
Nineveh proclaimed a fast and repented; God turned from His wrath.
But let man and beast be covered with sackcloth, and cry mightily unto God: yea, let them turn every one from his evil way, and from the violence that is in their hands.
Nineveh proclaimed a fast and repented; God turned from His wrath.
And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did it not.
Nineveh proclaimed a fast and repented; God turned from His wrath.