The Sadducees, the priestly party that denied the resurrection of the dead (Acts 23:8), build their riddle on levirate marriage: the Torah's command that a man marry his brother's childless widow (Deuteronomy 25:5-10, the law behind Ruth; the Mishnah's tractate Yevamot regulates its cases). Seven brothers, one widow: “in the resurrection whose wife shall she be?” Jesus answers them from the Torah alone, the canon they granted: “I AM the God of Abraham” (Exodus 3:6), the living God of living men. Note where the parties stand: the Pharisees affirmed the resurrection so strongly that the Mishnah excludes from the world to come anyone who says the resurrection is not from the Torah (Sanhedrin 10:1). On this doctrine the Pharisaic tradition and Christian confession stand together against the Sadducees.

The lawyer's question that follows, “which is the great commandment?”, belongs to a genuine rabbinic genre: the search for a kelal gadol, a great governing principle. Hillel, asked to teach the whole Torah while a challenger stood on one foot, answered “what is hateful to you, do not do to your fellow; that is the whole Torah, the rest is commentary; go and learn” (Shabbat 31a); Rabbi Akiva later called “love your neighbor as yourself” the all-embracing principle of the Torah (Sifra on Leviticus 19:18). Jesus' first answer IS the Shema, the confession every observant Jew prays morning and evening (Deuteronomy 6:4-5), joined to Leviticus 19:18. The materials are the tradition's own; what is His alone is the authority with which He joins and ranks them, and the counter-question He then asks from Psalm 110: whose son is the Messiah?