1 sn Most of the roofs in the NT were flat roofs made of pounded dirt, sometimes mixed with lime or stones, supported by heavy wooden beams. They generally had an easy means of access, either a sturdy wooden ladder or stone stairway, sometimes on the outside of the house.
2 sn The swiftness and devastation of the judgment will require a swift escape. There is no time to come down from one’s roof and pick up anything from inside one’s home.
3 sn An allusion to Gen 19:26. The warning about Lot’s wife is not to look back and long to be where one used to be. The world is being judged, and the person who delays or turns back will be destroyed.