1. The term "levirate marriage" has nothing to do with Levi, but is derived from the Latin word, 'levir,' for "brother-in-law."
2. See, e.g., T. Wallis, The Elder in the City (Atlanta, GA: Society of Biblical Literature, 2001), 238-42.
3. R. Westbrook, Property and the Family in Biblical Law (JSOTS, 113; JSOT Press, 1991), 87-89. Cf., J. A. Thompson, Deuteronomy (Tyndale Old Testament Commentaries; Leicester: Inter-Varsity Press, 1974), 251.
4. It is debated whether the practice in Ruth represents a custom different from levirate marriage; for a discussion of this debate, see F. Bush, Ruth, Esther (WBC, 9; Dallas, TX: Word Books, 1996), 221-27.
5. As the Gen 38 narrative shows, a young childless widow is left in a highly vulnerable position—Tamar was conveniently shelved by Judah indefinitely in her father's household. As S. Niditch points out, a levirate marriage "reaffirms the young widow's place in the home of her husband's people" ("The Wronged Woman Righted," Harvard Theological Review 72 (1979):144).
6. Both the first and the second named person (Er and Onan, respectively) who were specifically said to be put to death by Yhwh for their wickedness hailed from the tribe of Judah. Yet out of this cuckoo's nest God choose for his Redeemer to come.