When they had brought them outside he said, “Flee for your life! Do not look behind you, nor stop anywhere in the Plain; flee to the hills, lest you be swept away.” (19:17)
The Ohr Hachaim asks, why wasn't Lot permitted to look back when he fled the land of Sedom. The Ohr Hachaim answers by explaining that Chazal teach us that a record and description of a person's sins are written upon his face. A prosecuting angel can see and read one's sins just by looking at a person. Lot was guilty of many of Sedom's crimes. Indeed, Lot in his own merit would not have been saved. It was only in the merit of Avraham that he was spared. If Lot would have turned around and been seen by the destructive angels they would have seen his face and been presented with a description of his crimes. They would have no choice but to punish him together with the sinners of Sedom.
