'Symbols' in the Bible

You should tie them as a reminder on your forearm and fasten them as symbols on your forehead.

Fix these words of mine into your mind and being, and tie them as a reminder on your hands and let them be symbols on your forehead.

Behind the door and doorpost you put your symbols. Indeed, you depart from me and go up and invite them into bed with you. You purchase favors from them, you love their bed, and gaze longingly on their genitals.