A Covenant Sacrifice
As the years passed, and Abraham wondered about the birth of the promised heir, he queried the Lord for an assurance respecting his expectation. He no doubt wished to be certain he understood the promise correctly.
God renewed his word, affirming that as the innumerable stars above, “so shall thy seed be.” (Genesis 15:5)
God also instructed Abraham to perform what may seem a strange ritual. He directed that various animals be sacrificed, divided (except for the birds as Leviticus 1:17), and spread out on the ground. “And it came to pass, that, when the sun went down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces. In the same day the Lord made a covenant with Abram… ” (Genesis 15:16, 17)
Why this strange performance? Apparently God was condescending to a recognized custom of the time (as well as directing a type, on which perhaps more at a later date). When a solemn pact was made in ancient times the contract was solemnized, made binding, ratified, when the contracting parties walked between the pieces of a slain animal, the “covenant sacrifice” or “covenant victim.”
Thomas Scott’s commentary: “As the ratification of a covenant between the Lord and his servant was intended, the animals were divided asunder, the birds alone excepted: because the form of covenanting required, that the persons concerned should pass between the parts of the sacrifice: perhaps intimating, that he who broke the covenant, might expect in like manner, to be cut asunder by the avenging sword of justice. The Gentiles, as well as the Jews, used a form of this kind in confirming covenants and treaties; which custom might perhaps be derived by tradition from this transaction; or the Lord saw good, in this instance, to condescend as far as practicable, to a custom already established.” (Note Abraham did not pass between the pieces, but that which represented the Divine presence did: the burning lamp. This was a unilateral agreement. God promised to do something. Abraham had no conditional part, having demonstrated his faith previously per Genesis 12:1-4.)
Another example of this practice is in Genesis 21:27:
“And Abraham took sheep and oxen, and gave to Abimelech, and they two solemnized a covenant.” (Rotherham)
Rotherham’s footnote on “solemnized a covenant” is “cut, because of the cutting up and distribution of the flesh of the victim.”
Adam Clarke’s comment: “the word is Kareth Berith – to cut a covenant, or rather the covenant sacrifice; for as no covenant was made without one, and the creature was cut in two that the contracting parties might pass between the pieces, hence cutting the covenant signified making the covenant.”
He goes on to explain that the Latin words of the Romans used for making contracts had root meanings of “cutting its throat,” or “knocking it down” with a stone axe, from the custom of slaying a sacrifice to ratify the agreement.
A third scripture example of the custom is in Jeremiah 34:18-20.
With the background of this custom, the Diaglott version of Hebrews 9:16, 17 makes good sense. “For where a Covenant exists, the Death of that which has ratified it is necessary to be produced; because a Covenant is firm over dead victims, since it is never valid when that which ratifies it is alive.”