For he supposed his brethren would have understood him,.... From his being an Hebrew in such high life; from his wonderful birth, and miraculous preservation in his infancy, and education in Pharaoh's court; and from the promise of God that he would visit them and save them:
how that God by his hand would deliver them: wherefore he was the more emboldened to kill the Egyptian, believing that his brethren would make no advantage of it against him; but look upon it as a beginning and pledge of their deliverance by him:
but they understood not; or "him not", as the Ethiopic version reads; they did not understand that he was to be their deliverer, or that this action of his was a token of it.