Shanan (שָׁנַן) means to whet or sharpen (as a sword or arrow), and by extension to teach sharply and repeatedly — to inculcate by diligent repetition. It appears about 9 times in the OT. The most celebrated occurrence is Deuteronomy 6:7, where Moses commands parents to shanan God's commandments to their children.
The word is related to shen (H8127, tooth) — both the sharpened implement and the sharp repetition. Teaching that is shanan is not shallow or occasional; it is thorough, penetrating, and persistent.
Deuteronomy 6:7 is the heart of Israel's educational theology: "You shall teach them [shanan] diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise." This is a picture of comprehensive, life-integrated discipleship — not classroom instruction only, but the saturation of family life with God's word.
The Shema (vv.4-5) commands total love of God; shanan (v.7) is its transmission mechanism. Faith is not just believed — it is practiced, discussed, modeled, and repeated until it is written on the heart (Jer. 31:33). This principle underlies the New Testament pattern of discipleship: Jesus didn't lecture his disciples — he lived with them for three years, showing them what the Kingdom looks like in daily life. "Teaching them to observe all that I have commanded you" (Matt. 28:20) is shanan in its fullest form.