'Dirt' in the Bible

On the third day a man arrived from the camp of Saul with his clothes torn and dirt on his head. When he approached David, the man threw himself to the ground.

When David reached the summit, where he used to worship God, Hushai the Arkite met him with his clothes torn and dirt on his head.

So David and his men proceeded along the road as Shimei was going along the ridge of the hill opposite him. As Shimei went, he cursed David, and threw stones and dirt at him.