My son (b'ni) serves to externally connect this discourse with the preceding. Forget not my law. This admonition bears a strong resemblance to that in Proverbs 1:8, though the terms employed are somewhat different, torah and mits'oth here occupying the place respectively of musar and torah in that passage.
My law (torathi), is literally, my teaching, or doctrine, from the root yarah, "to teach." The torah is the whole body of salutary doctrine, and designates "Law" from the standpoint of teaching. Forgetting here is not So much oblivion arising from defective memory, as a wilful disregard and neglect of the admonitions of the teacher.
Thine heart (libekha); Vulgate, cor; LXX; καρδία and so the sum total of the affections. Keep; yitstsor, from notsar, "to keep, or observe that which is commanded." The word is of frequent occurrence in the Proverbs, and appears about twenty-five times.
My commandments (mits'othay); Vulgate, praecepta mea; LXX; τὰ ῥήματα μου; i.e. my precepts. The Hebrew verb from which it is derived means "to command, or prescribe." The law and commandments here alluded to are those which immediately follow, from verse 3 onwards.
The three main ideas combined in this verse are remembrance, affection, and obedience. Remembering the law or teaching will depend, to a large extent, on the interest felt in that law; and the admonition to "forget not" is an admonition to give "earnest heed," so that the law or teaching may be firmly fixed in the mind.
In using the words, "let thy heart keep," the teacher goes to the root of the matter. There may be an historical remembrance of, or an intellectual assent to, the commandments, but these are insufficient, for the keeping of the commandments must be based on the recognition of the fact that the affections of the heart are to be employed in the service of God, the keeping of the commandments is to be a labour of love.
Again, the expression, "keep my commandments," implies, of course, external conformity to their requirements: we are "to observe to do them" (Deuteronomy 8:1); but it implies, further, spiritual obedience, i.
e. an obedience with which love is combined (Deuteronomy 30:20), and which arises from the inward principles of the heart being in harmony with the spirit of the commandments (see Wardlaw).