And he took unto him all these, and divided (a word occurring only here in Genesis, and supposed by Michaelis to have been taken by Moses from the ancient document from which he transcribed this portion of his work.
The word is afterwards found in So Genesis 2:17, and Jeremiah 34:18) them in the midst,—μέσα (LXX.); in equal parts (Onkelos)—and laid each piece one against another: but the birds divided he not. So afterwards in the Mosaic legislation (Le Genesis 1:7).
Wordsworth detects in the non-dividing of the birds an emblem of "the Holy Spirit, the Spirit of peace and love; which is a Spirit of unity, and of "Christ's human spirit, which was not divisible." Kalisch, with more probability, recognizes as the reason of their not being divided the fact that such division was not required, both fowls being regarded as one part of the sacrifice only, and each, as the half, being placed opposite the other.
Wordsworth numbers seven parts in the sacrifice, and sees a symbol of completeness and finality, the number seven being the root of shaba, to swear; Kalisch reckons four, which he regards as "denoting perfection, but rather the external perfection of form than the internal one of the mind," and pointing "to the perfect possession of the Holy Land."
The ritual here described is the same which was afterwards observed among the Hebrews in the formation of covenants (cf. Genesis 34:18), and appears to have extensively prevailed among heathen nations.