The thought of Proverbs 3:3 is carried step further. No outward charm, but the law of obedience, shall give safety to the traveler, when he sleeps or when he wakes.

Bind them continually upon thine heart - See on Proverbs 3:3 (note). And see a similar command, to which this is an allusion, Deuteronomy 6:6-8 (note).

Bind them continually upon thine (i) heart, [and] tie them about thy neck.
(i) (Proverbs 3:3).

Bind them continually upon thine heart,.... Not upon the head or arm, as the words of the law were to be bound, Deuteronomy 6:3; to which there seems to be an allusion; and which may confirm the sense of the words given, that this respects the law of God itself, and the precepts of it, instructed in by parents; but they should be bound upon the heart, and have an abiding place in the understanding, affections, memory, and will;
and tie them about thy neck; as an ornament, instead of a necklace of pearl, or chains of gold; they should be so far from being thought burdensome and troublesome, that they should be reckoned comely and graceful; see Proverbs 1:9.

Bind them - Constantly remember, and duly consider them.