'Sackcloth' in the Bible

Wail like a virgin girded with sackclothFor the bridegroom of her youth.

Gird yourselves with sackclothAnd lament, O priests;Wail, O ministers of the altar!Come, spend the night in sackclothO ministers of my God,For the grain offering and the drink offeringAre withheld from the house of your God.