'Sackcloth' in the Bible

So put on sackcloth! Mourn and wail, saying, 'The fierce anger of the Lord has not turned away from us!'"

So I said, "Oh, my dear people, put on sackcloth and roll in ashes. Mourn with painful sobs as though you had lost your only child. For any moment now that destructive army will come against us."

For all of them will shave their heads in mourning. They will all cut off their beards to show their sorrow. They will all make gashes in their hands. They will all put on sackcloth.

Wail, you people in Heshbon, because Ai in Ammon is destroyed. Cry out in anguish, you people in the villages surrounding Rabbah. Put on sackcloth and cry out in mourning. Run about covered with gashes. For your god Milcom will go into exile along with his priests and officials.