'Hollow' in the Bible

And on the way he came to a place where sheep were kept, where there was a hollow in the rock; and Saul went in for a private purpose. Now David and his men were in the deepest part of the hollow.

And after that David came out of the hollow rock, and crying after Saul said, My lord the king. And when Saul gave a look back, David went down on his face and gave him honour.

Look! you have seen today how the Lord gave you up into my hands even now in the hollow of the rocks: and some would have had me put you to death, but I had pity on you: for I said, Never will my hand be lifted up against my lord, who has been marked with the holy oil.