Genesis 21:29

And Abimelech said unto Abraham
Observing what he had done, and not knowing the design of it: what [mean] these seven ewe lambs which thou hast set by themselves?
he understood what the sheep and oxen were for, that they were presents to him, at least some of them, and the rest were for the solemnizing and ratifying the covenant between them; but what these were for he could not devise.