John Wesley on Romans 11:2

God hath not rejected that part of his people whom he foreknew - Speaking after the manner of men. For, in fact, knowing and foreknowing are the same thing with God, who knows or sees all things at once, from everlasting to everlasting. Know ye not - That in a parallel case, amidst a general apostasy, when Elijah thought the whole nation was fallen into idolatry, God "knew" there was "a remnant" of true worshippers.