Verses 4 and 5 are the Shema (Hebrew for “Hear,” the passage's first word): “Hear, O Israel: the LORD our God, the LORD is one.” It is the closest thing Judaism has to a creed, prayed morning and evening by observant Jews to this day; the Mishnah, the first code of Jewish oral law (about AD 200), opens its very first page with the question of when the evening Shema is recited (Berakhot 1:1). When a lawyer asks Jesus which commandment is greatest, His answer begins with this text (Matthew 22:37).

The commands to bind these words “on your hand” and “between your eyes” and to write them “on your doorposts” are kept physically. Tefillin (called phylacteries in the Gospels) are two small leather boxes containing Scripture passages, bound with straps to the arm and forehead during weekday morning prayer. A mezuzah is a small case fixed to the doorpost of a Jewish home holding this passage on parchment. Jesus never criticizes either practice; His woe falls on tefillin made extra wide to be seen (Matthew 23:5), ostentation in a good thing, not the thing itself.