Bible Dictionary · S
Sackcloth
Cloth made of black goats’ hair, coarse, rough, and thick, used for sacks, and also worn by mourners (Gen 37:34; Gen 42:25; 2 Sam 3:31; Esth 4:1, Esth 4:2; Ps 30:11, etc.), and as a sign of repentance (Matt 11:21). It was put upon animals by the people of Nineveh (Jonah 3:8).
From Easton’s Bible Dictionary (1897), by Matthew George Easton.