John Calvin Commentary Deuteronomy 11:18

"Therefore shall ye lay up these my words in your heart and in your soul; and ye shall bind them for a sign upon your hand, and they shall be for frontlets between your eyes." — Deuteronomy 11:18 (ASV)

Therefore you shall lay up these my words. He again demands their serious attention, lest, if the doctrine he presents should be received only lightly and carelessly, it should quickly be forgotten. For to lay up in, or on, the heart is the same as to hide deeply in it. Although, where the word “soul” is added, the “heart” refers to the mind, or the intellectual faculties. In short, he commands them to have the Law not only impressed on the mind but also embraced with sincere affection.

Next, he commands that aid to memory which we have just considered: namely, that they should wear the precepts on their arms and foreheads, as if God were constantly meeting them to arouse their senses. For (as has been said) God had no regard for the bands themselves, but wanted them to be seen on their arms and foreheads for another purpose, namely,²³⁶ to suggest and renew their care for religion.

Again, He appointed these precepts to serve as ornaments, in order to accustom the people to take their chief delight in meditating on the Law. Thus, that foolish ambition is sufficiently refuted—when hypocrites sought a reputation for holiness through their fringes and other frivolities—as well as the gross error of the entire people in thinking that they discharged their duty to God by their outward dress.

What follows—that the precepts should be written on the gates of their cities and on their private houses—tends to the same end. For we have said that since human minds are prone to vanity and are easily distracted by countless allurements, they need such supports to hold them back.

And this purpose is plainly expressed when He commands them individually to speak of the precepts of the Law—whether they are sitting at home, walking along the way, lying down, or rising up—because without diligent practice, it usually happens that whatever people have once learned is soon lost. He also adds another effect of this diligence: namely, that not only should each of them ensure their own individual benefit, but they should also teach their children, so that God’s Law would always be maintained in its strength by perpetual succession.

²³⁶ C’est de renouveler aux enfans d’Israel la pensee, qu ils devoyent avoir de s’enquerir de sa volonte;” to renew in the children of Israel the care they ought to have in inquiring as to His will. — Fr.