Since remaining in S'dom was fraught with danger, why did Lot delay?
Rashi: The answer is human nature - he was being told to leave without his money, a request that was too much for him.
Why indeed, was Lot not permitted to take his money with him?
Rashi: Because on whatever basis Hashem was saving him, it was sufficient to save him, but not his money, as the very next Pasuk hints - "Save yourself!" (but not your money).
What is the significance of 'Hashem's pity' here?
Ramban #1: To teach us that Lot was not being spared on his own merit but because Hashem had taken pity upon him.
Ramban #2: The angels were pushing him to escape before Hashem's patience ran out and he would be destroyed together with the other inhabitants of S'dom.
Seforno: Even though his salvation was based on the merit of Avraham, 1 his delaying tactics would have brought about his own death, were it not for the fact that Hashem had taken pity on him - bearing in mind that his procrastination was due, not to an act of rebellion, but to his laziness.
See Pasuk 29.
Seeing as Refael was sent to save Lot and Gavriel to overturn Sedom, what right did the latter have (here and in the following Pesukim) to assist in leading Lot out of the town?
Or ha'Chayim: He only assisted Refael, and we have a principle 'Someone who merely assists is not considered as having performed the act. Moreover, the reason that he assisted was because Refael would not have allowed him to overturn Sedom as long as Lot was still inside the town, in which case what he did was a preparation for the destruction, which was therefore part of his Shelichus.
The previous verse called them angels. Why does it say "the men held Lot"?
Moshav Zekenim: Angels are of fire. They needed to assume a human form, lest they burn him when holding him.