Deuteronomy 6:8

“And thou shalt bind them for a sign upon thine hand, etc.] As a man ties anything to his hand for a token, that he may remember somewhat he is desirous of; though the Jews understand this literally, of binding a scroll of parchment, with this section and others written in it, upon their left hand, as the Targum of Jonathan here interprets the hand: and they shall be as frontlets between thine eyes; and which the same Targum interprets of the Tephilim, or phylacteries, which the Jews wear upon their foreheads, and on their arms, and so Jarchi; of which (see Gill on “<402305>Matthew 23:5”).”

“By adopting and regulating customary usages (e. g. Egyptian) Moses provides at once a check on superstition and a means of keeping the Divine Law in memory. On the “frontlets,” the “phylacteries” of the New Test. Matthew 23:5, see Exodus 13:16. On Deuteronomy 6:9; Deuteronomy 11:20 is based the Jewish usage of the mezuzah. This word denotes properly a door-post, as it is rendered here and in Exodus 12:7, Exodus 12:22; Exodus 21:6 etc. Among the Jews however, it is the name given to the square piece of parchment, inscribed with Deuteronomy 6:4-9; Deuteronomy 11:13-21, which is rolled up in a small cylinder of wood or metal, and affixed to the right-hand post of every door in a Jewish house.…”

“Thou shalt bind them - Thou shalt give all diligence, and use all means to keep them in thy remembrance, as men often bind something upon their hands, or put it before their eyes to prevent forgetfulness of a thing which they much desire to remember. Deuteronomy 6:13”

“6:8 Tie them: The Lord’s commandments (6:6) were to be as interwoven into the hearts and minds of children as though they were tied to them. Eventually, this figurative phrase in Judaism was practiced literally by wrapping the forearm with cords representing the Torah (see study note on 4:44). • wear them: This figure of speech was represented literally in later Judaism by a small box containing a few brief Torah texts. The box and its contents (Hebrew tefillin; Greek phylactery) were reminders of the need to teach and obey the covenant (cp. 11:18; Matt 23:5).”

“Deu 11:18; Exo 13:9, Exo 13:16; Num 15:38, Num 15:39; Pro 3:3, Pro 6:21, Pro 7:3; Mat 23:5; Heb 2:1 Deuteronomy 6:9”