Genesis 19:15-17 meaning

The next few verses have a sense of urgency in order to get Lot to safety. However, it will take some persuasion to get Lot out of town, the angels urged Lot. Lot was spared because the compassion of the LORD was upon him. Also because "God remembered Abraham" (verse 29) and sent Lot out of the city.

Lot hesitates but the angels force him to move. Lot hesitated. We are not told why. But there are many possibilities. We can speculate that he wanted to stay behind and convince his sons-in-law. Perhaps their argument began to influence Lot, and he began to have doubts. We can imagine his daughters would not be keen to leave their fiancés. We will find out later that his wife did not want to leave, perhaps she urged him to stay. It could be that he was worried about his possessions, he came to the area in the first place because his herds were so extensive. 

Safety now lies outside of the city, so, the men seized his hand…and put him outside the city. The angels did not hesitate, Lot and his wife and daughters were dragged physically to safety. This the second time the angels had to grab and rescue Lot (verse 10). Leaving the city was a type of salvation, deliverance from judgment. Had Lot not departed, he would be be swept away in the punishment of the city.  God was merciful and Lot was brought out of the city, the compassion of the Lord was upon him. He was also spared for Abraham's sake (Genesis 18:23, 19:29). 

The men instructed Lot and his family, "Do not look behind you." In order to look back, one would have to stop in the plain, short of the mountain's safety. There was no time to linger or watch the destruction. They also instructed not to stay anywhere in the valley. Their lives depended on reaching the mountains. The mountains to which Lot was told to flee are on the Moabite Plateau east of the Dead Sea. Today they stand between 2,500 and 3,000 feet above the Dead Sea. They were out of the area in the plain that would be totally destroyed. The plain would soon be swept away. However, Lot will beg to stay in the small city of Zoar (verse 20).