Proverbs 6:21 (NKJV) — 21 Bind them continually upon your heart; Tie them around your neck.
Keep them constantly in mind. These instructions are obviously symbolic terms to describe the constant attention that should be given to the father’s commandment and the mother’s law. The Pharisees, by their strict literalism, attempted to fulfill similar commands in the law of Moses by physically attaching phylacteries to their forearms and foreheads when praying. But it is possible to have copies of the Scriptures attached to one’s person and still not have the Word hidden in one’s heart.