Deuteronomy 6:8
6 These words I am commanding you today must be kept in mind, 7 and you must teach them to your children and speak of them as you sit in your house, as you walk along the road, as you lie down, and as you get up. 8 You should tie them as a reminder on your forearm and fasten them as symbols on your forehead. 9 Inscribe them on the doorframes of your houses and gates. 10 Then when the Lord your God brings you to the land he promised your ancestors Abraham, Isaac, and Jacob to give you—a land with large, fine cities you did not build,
Proverbs 7:3
1 My child, devote yourself to my words and store up my commands inside yourself. 2 Keep my commands so that you may live, and obey my instruction as your most prized possession. 3 Bind them on your forearm; write them on the tablet of your heart. 4 Say to wisdom, “You are my sister,” and call understanding a close relative 5 so that they may keep you from the adulterous woman, from the loose woman who has flattered you with her words.
Notes and References
"... The terms “sign,” “reminder,” and “symbol” evoke some material object that serves to jog the memory, but they do not in themselves require a literal meaning for these verses. Rashbam actually considered the “deep, straightforward meaning” of the verses to be metaphorical. He adduced, in support, Song of Songs 8:6 ... Abraham Ibn Ezra mentions, but rejects, this figurative interpretation, which its proponents bolstered by citing additional biblical sources such as “For they are a graceful wreath upon your head, / A necklace about your throat” (Proverbs 1:9). “Let fidelity and steadfastness not leave you; / Bind them about your throat, / Write them on the tablet of your mind”. “Tie them over your heart always; / Bind them around your throat”. Other texts of the same order are Proverbs 7:3 as well as Jeremiah 17:1 and 31:32. Apparently, both the Samaritans and the medieval Jewish sect of Karaites also took the instructions of Exodus 13:9,16 metaphorically, for they do not have tefillin. Traditional rabbinic exegesis, however, interpreted Exodus 13:9,16 literally as enjoining the wearing of tefillin. This understanding is upheld by two other texts in the Torah that reiterate the precept. Deuteronomy 6:8, which is part of the section that has traditionally become known as the Shema, states: “Bind them [i.e., God’s teachings, v.6] as a sign on your hand, and let them serve as a symbol on your forehead.” A literal meaning is here favored by the immediately adjacent verse: “Inscribe them on the doorpost of your house and on your gates.” ..."
Sarna, Nahum M. Exodus: The Traditional Hebrew Text with the New JPS Translation (p. 270) Jewish Publication Society, 1991