2 Samuel 12:16

Then the king arose, and tare his garments, and lay on the earth; and all his servants stood by with their clothes rent.

And he was three days without sight, and neither did eat nor drink.

And it came to pass, when Ahab heard those words, that he rent his clothes, and put sackcloth upon his flesh, and fasted, and lay in sackcloth, and went softly.

And he said, While the child was yet alive, I fasted and wept: for I said, Who can tell whether God will be gracious to me, that the child may live?

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.

And in that day did the Lord God of hosts call to weeping, and to mourning, and to baldness, and to girding with sackcloth:

Who can tell if God will turn and repent, and turn away from his fierce anger, that we perish not?

And call upon me in the day of trouble: I will deliver thee, and thou shalt glorify me.

When I wept, and chastened my soul with fasting, that was to my reproach.

Lord, in trouble have they visited thee, they poured out a prayer when thy chastening was upon them.

Though wickedness be sweet in his mouth, though he hide it under his tongue; Though he spare it, and forsake it not; but keep it still within his mouth: Yet his meat in his bowels is turned, it is the gall of asps within him.

Therefore also now, saith the Lord, turn ye even to me with all your heart, and with fasting, and with weeping, and with mourning: And rend your heart, and not your garments, and turn unto the Lord your God: for he is gracious and merciful, slow to anger, and of great kindness, and repenteth him of the evil. Who knoweth if he will return and repent, and leave a blessing behind him; even a meat offering and a drink offering unto the Lord your God?