What does sack-cloth upon his loins mean?

"Sackcloth upon his loins" refers to wearing a rough, coarse fabric, traditionally made from goat's hair, as a sign of mourning, repentance, or humility in biblical and ancient contexts. It symbolizes deep sorrow or distress, often used during periods of grief or penitence. The act of wearing sackcloth was a way to publicly express one's emotional state and seek forgiveness or pity.