Matthew Poole and continuators on Genesis 15:10

10 And he took unto him all these, and divided them in the midst , and laid each piece one against another : but the birds divided he not x.

(i. e.) Abram: who by divine instinct and precept did all this which here follows.

Into two equal parts. This was done for two reasons, 1. To represent the torn and distracted condition in which his seed was to ly for a season. 2. To ratifie God's covenant with Abram and his seed: for this was a rite used in making covenants, as appears both from Scripture, Ier. 34. 18. and other Authors.

Partly to encourage hope, that God would in his time put those parts together, and unite those dry bones (to which the Israelites are compared, Ezek. 37.) and cloth them with flesh; and partly that the persons entring into covenant, might pass between those parts, and so testifie their union and conjunction in one and the same sacrifice. Either because there were two Birds, and the one was laid against the other, which answered to the division of the larger Creatures: or because they belonged not to the Ceremony of the Covenant, but were for the use of sacrifice, wherein they were to be offered whole, as afterwards was prescribed, Levit. 1. 15, 17.