And when the fowls came down. Although the sacrifice was dedicated to God, yet it was not free from the attack and the violence of birds. So neither are the faithful, after they are received into the protection of God, so covered with his hand, as not to be assailed on every side; since Satan and the world cease not to cause them trouble. Therefore, in order that the sacrifice we have once offered to God may not be violated, but may remain pure and uninjured, contrary assaults must be repulsed, with whatever inconvenience and toil.

And when the fowls - העיט haayit, birds of prey, came down upon the carcasses to devour them, Abram, who stood by his sacrifice waiting for the manifestation of God, who had ordered him to prepare for the ratification of the covenant, drove them away, that they might neither pollute nor devour what had been thus consecrated to God.

And when the fowls came down upon the carcasses,.... Upon the birds, as Aben Ezra and Ben Melech interpret it, whose carcasses were whole; or rather upon the divided carcasses of the animals, and indeed on both: this is to be understood of birds of prey, as eagles, vultures, kites, crows, &c. and are an emblem of the Egyptians chiefly, and other enemies of Israel, who came upon them to devour them; so the Targum of Jonathan,"and the idolatrous nations descended, who were like to an unclean fowl, to spoil the goods of the Israelites;''and likewise the Targum of Jerusalem,"this unclean fowl are the idolatrous kingdoms of the earth:"
Abram drove them away: that they might not settle upon the carcasses, and devour them: the Septuagint version is, "Abram sat with them"; he sat by the carcasses and watched them, that no hurt came to them, and to take notice of them, and consider and learn what they were an emblem of. The Jews (l) also observe, that"Abram sat and waved over them with his napkin or handkerchief, that the birds might not have power over them until the evening.''This may respect not the merit of Abram, as the above Targums, by which his posterity were protected, and the designs of their enemies frustrated; but the effectual fervent prayer of Abram, his prayer of faith for them, in answer to which they were delivered out of the hands of the Egyptians, and other enemies, whom Abram foresaw they would be distressed with.
(l) Pirke Eliezer, ut supra. (c. 28)

"Then birds of prey (העיט with the article, as Genesis 14:13) came down upon the carcases, and Abram frightened them away." The birds of prey represented the foes of Israel, who would seek to eat up, i.e., exterminate it. And the fact that Abram frightened them away was a sign, that Abram's faith and his relation to the Lord would preserve the whole of his posterity from destruction, that Israel would be saved for Abram's sake (Psalm 105:42).