Other commentators on this passage have offered other possible scripture references for the word epigraphy; Giblin suggests Proverbs 7:3 or Jeremiah 38:33 (Septuagint 31:33)—both of which refer to God’s inscribing his commandments on one’s heart—or Isaiah 44:5—in which the service of God is described in terms of writing “I belong to God” on the hand. (See Charles Homer Giblin, S.J., “‘The Things of God’ in the Question Concerning Tribute to Caesar [Lk 20:25; Mk 12:17; Mt 22:21],” Catholic Biblical Quarterly 33 [October 1971], pp. 510–527.) I maintain, however, that the text underlying Jesus’ reference to “inscription” is Exodus 13:9, because it would be much more in keeping with halakhic tradition to base a ruling on the Torah than on Proverbs, Jeremiah or Isaiah.

Based on Exodus 13:9, observant Jews wear tefillin—small leather boxes carrying parchment inscribed with Exodus 13:1–10 (and three other biblical passages)—on their left arm and forehead during morning prayer services.