Among ancient commentators, for example, Philo, On the Sacrifices of Abel and Cain 52 and 72, trans. in Philo, vol. 2, ed. F.H. Colson and G.H. Whitaker, Loeb Classical Library(Cambridge, MA: Harvard Univ. Press, 1929) Genesis Rabbah 22.5. Among modern commentators, for example, Umberto Cassuto, A Commentary on the Book of Genesis (Jerusalem: Magnes, 1961), p. 205; E.A. Speiser, Genesis, Anchor Bible 1 (Garden City, NY: Doubleday, 1964), p. 30; Nahum Sarna, Understanding Genesis (New York: Schocken, 1966), pp. 29–30; Gordon J. Wenham, Genesis 1–15, Word Biblical Commentary (Waco, TX: Word Books, 1987), pp. 101–102.