'Really' in the Bible

Then Isaac said to Jacob, "Please, come near and let me feel you, my son. {Are you really} my son Esau or not?"

And he said, "{Are you really} my son Esau?" And he said, "I [am]."

Then his brothers said to him, "Will you really rule over us?" And {they hated him even more} on account of his dream and because of his words.