Adam Clarke's Commentary on the Bible - Genesis 15:17
Smoking furnace and a burning lamp - Probably the smoking furnace might be designed as an emblem of the sore afflictions of the Israelites in Egypt; but the burning lamp was certainly the symbol of the Divine presence, which, passing between the pieces, ratified the covenant with Abram, as the following verse immediately states. read more
Adam Clarke's Commentary on the Bible - Genesis 15:16
In the fourth generation - In former times most people counted by generations, to each of which was assigned a term of years amounting to 20, 25, 30, 33, 100, 108, or 110; for the generation was of various lengths among various people, at different times. It is probable that the fourth generation here means the same as the four hundred years in the preceding verse. Some think it refers to the time when Eleazar, the son of Aaron, the son of Amram, the son of Kohath, came out of Egypt, and... read more