By which symbol God designed to represent, either,
1. The future state of Abram's seed; the smoking furnace signifying Israel's misery in the iron furnace of Egypt, as it is called, Jeremiah 11:4; and the burning lamp noting their deliverance, or light shining out of darkness. Or,
2. His own presence; for God is called a consuming fire, Hebrews 12:29; and both smoke and fire are elsewhere mentioned as the signs and means of God's appearance. See Exodus 3:2, Exodus 19:9,16,18 20:18. And this sense seems to be favoured by the following words, it being the custom of persons entering into covenant to pass between such pieces as hath been said; and because God hath no body which could visibly do so, therefore he doth it in this type or shadow.