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."
Genesis 18:30
Surrounding context
18:29 And he spoke to Him yet again and said, "Suppose there should be forty found there?" So He said, "I will not do it for the sake of forty."
18:30 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."
18:31 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."