Oh let not the Lord be angry — The importunity which believers use in their addresses to God is such, that if they were dealing with a man like themselves, they could not but fear that he would be angry with them. But he with whom we have to do is God and not man, and he is pleased when he is wrestled with. But why then did Abraham leave off asking when he had prevailed so far as to get the place spared if there were but ten righteous in it? Either, Because he owned that it deserved to perish if there were not so many: as the dresser of the vineyard, who consented that the barren tree should be cut down if one year's trial more did not make it fruitful, Luke 13:9. Or, Because God restrained his spirit from asking any farther. When God hath determined the ruin of a place, he forbids it to be prayed for, Jeremiah 7:16.
Related Commentaries of Genesis 18:30
Genesis 18:30
30 And he said unto him, Oh let not the Lord be angry, and I will speak: Peradventure there shall thirty be found there. And he said, I will not do it, if I find thirty there.