Targum Pseudo-Jonathan on Genesis 15:10 gives Abraham the work of a careful butcher and a careful theologian at the same time. He brings the five animals. He divides them down the middle. He arranges each half opposite its fellow, a geometry of matched pieces, like courtrooms or like armies facing each other. And then, the Targum says plainly, the fowl he divided not.
The arrangement is not random. The split animals correspond to the empires that will rise and fall across Israel's history — each one divided because each one is destined to be cut in two. The dove and the pigeon, though, stay whole. They are Israel. A nation God may discipline, but never halve.
The Maggid hears a promise in the unbroken birds. Enemies come in pieces; the beloved stays entire. Even in the midst of a vision full of smoke and terror (Genesis 15:12, 15:17), the small intact body of a dove is the quietest, most durable reassurance in the chapter (Genesis 15:10). A covenant is being cut around Israel, not through her.