C. F. Keil and Franz Delitzsch on Genesis 19:29

Gen 19:29

For on the destruction of these cities, God had thought of Abraham, and rescued Lot. This rescue is attributed to Elohim, as being the work of the Judge of the whole earth (Gen 18:25), and not to Jehovah the covenant God, because Lot was severed from His guidance and care on his separation from Abraham. The fact, however, is repeated here, for the purpose of connecting with it an event in the life of Lot of great significance to the future history of Abraham’s seed.