'Covering' in the Bible

And David went up the slopes of the Mount of Olives weeping all the way, with his head covered and no shoes on his feet: and all the people who were with him, covering their heads, went up weeping.

And the woman took and spread a covering over the well's mouth, and spread ground corn thereon; and the thing was not known.

But the king, covering his face, gave a great cry, O my son Absalom, O Absalom, my son, my son!