Genesis 15:11

And when the fowls came down upon the carcases, Abram drove them away.

Abraham stood guard over the sacrificial animals he had offered, driving away the birds of prey that came down upon the carcasses. The victims had been divided in preparation for the covenant, and he kept watch beside them through the long delay until sunset. His vigilance kept the covenant offerings from being defiled or devoured before the covenant ceremony was completed.

That guarding of the sacrifice is a lesson in watching faithfully over one's dedication to God. As Abraham drove off the birds, so every thought of doubt is to be guarded against and driven away, lest the offering be spoiled.