Genesis 18:27, 30-32

Then Abraham answered and said, “Indeed now, I who am but dust and ashes have taken it upon myself to speak to the Lord

Then he said, “Let not the Lord be angry, and I will speak: Suppose thirty should be found there?” So He said, “I will not do it if I find thirty there.” And he said, “Indeed now, I have taken it upon myself to speak to the Lord: Suppose twenty should be found there?” So He said, “I will not destroy it for the sake of twenty.” Then he said, “Let not the Lord be angry, and I will speak but once more: Suppose ten should be found there?” And He said, “I will not destroy it for the sake of ten.”