Let not mercy and truth forsake thee: bind them about thy neck; write them upon the table of thine heart:

Let not mercy and truth leave thee, put them about thy neck, and write them in the tables of thy heart:

Let not mercy and good faith go from you; let them be hanging round your neck, recorded on your heart;

Let not kindness and truth forsake thee; Bind them about thy neck, write them upon the table of thy heart;

Let not mercy and truth abandon you: encircle them around your throat, and inscribe them on the tablets of your heart.

The two elements of a morally perfect character:
(1) "Mercy," shutting out all forms of selfishness and hate.
(2) "Truth," shutting out all deliberate falsehood, all hypocrisy, conscious or unconscious.
The words that follow possibly refer to the Eastern custom of writing sacred names on pieces of papyrus or parchment, and wearing them around the neck, as charms and talismans against evil. Compare, however, 1-Peter 3:3-4.

Let not mercy and truth forsake thee - Let these be thy constant companions through life.
Bind them about thy neck - Keep them constantly in view. Write them upon the table of thine heart - let them be thy moving principles; feel them as well as see them.

Let not (b) mercy and truth forsake thee: bind them about thy (c) neck; write them upon the table of thine (d) heart:
(b) By mercy and truth he means the commandments of the first and second table, or else the mercy and faithfulness that we ought to use toward our neighbours.
(c) Keep them as a precious jewel.
(d) Have them ever in remembrance.

Let not mercy and truth forsake thee,.... Or, forsake not them, and the exercise of them; show "mercy" to fellow creatures, to sinful men, to the bodies of men, by relieving their wants; and to their souls, by pitying and praying for them, and by giving them wholesome counsel and advice: to fellow Christians, sympathize with them in their troubles, put on bowels of compassion, be tenderhearted, and forgive offences; and, in a spirit of meekness, restore backsliders, for God will have mercy, and not sacrifice. Attend to "truth"; exercise faith on the Lord; cast not away your confidence; speak truth to your neighbour and brother; and hold fast the truth of the Gospel, and never depart from it. Though many interpreters understand this by way of promise, and as an encouragement to regard the doctrines and ordinances of Christ, rendering the words, "mercy and truth shall not forsake thee" (g); meaning the mercy and truth of God; the "mercy" of God in forgiving sin, in sympathizing under affliction, in helping in time of need, in supplying with all needful grace, and in bringing to eternal life; for the mercy of the Lord is from everlasting to everlasting, upon them that fear him, Psalm 103:17; the "truth" of God, his faithfulness in performing promises, never fails; the unbelief of man cannot make it of no effect; though we believe not, he abides faithful and true to every word of his; not one shall fail, or pass away; all shall be fulfilled; see Psalm 89:33; "all his paths are mercy and truth", and he never goes out of them, Psalm 25:10;
bind them about thy neck; as chains for ornament: not mercy and truth, just before mentioned, as may seem at first sight; but the law and commandments of wisdom, Proverbs 3:1; or the doctrines and ordinances of Christ; see Proverbs 1:8; reckon it as your greatest honour, glory, and beauty, that you steadfastly adhere to these things; nothing makes a believer look more lovely in conversation than a close regard to the truths of Christ, and a constant walking in his ordinances;
write them upon the table of thine heart; do not forget them, keep them in memory, and always retain a hearty affection for them; it is the Spirit's work to write them in the heart; and when they are there written, it is the work of saints, under a divine influence, to copy them over in life, and to show by their conduct and behaviour that they are written there; see Jeremiah 31:33. The allusion, in both phrases, is to the directions given about the law of Moses, Deuteronomy 6:8; and to the writing of his law on tables of stone: and it was usual with the ancients, in later times, to write on tables of wood; Solon's laws were written on tables of wood (h); and such were the "tabellae et pugillares" of the Romans, made of box, beech, and other sorts of wood, covered with wax, on which they wrote; See Gill on Habakkuk 2:2; but Solomon would have his law written on the fleshly tables of the heart, 2-Corinthians 3:3.
(g) "non derelinquent te", Piscator; "non deserent te", Michaelis; so Aben Ezra and Gersom. (h) Laert, Vit. Solon. A. Gell. Noet. Attic. l. 2. c. 12.

mercy and truth--God's faithfulness to His promises is often expressed by these terms (Psalm 25:10; Psalm 57:3). As attributes of men, they express integrity in a wide sense (Proverbs 16:6; Proverbs 20:28).
bind . . . write . . . heart--outwardly adorn and inwardly govern motives.

With this verse the doctrine begins; אל (not לא) shows the 3a does not continue the promise of Proverbs 3:2. חסד (R. חם, stringere, afficere) is, according to the prevailing usage of the language, well-affectedness, it may be of God toward men, or of men toward God, or of men toward one another - a loving disposition, of the same meaning as the N.T. ἀγάπη (vid., e.g., Hosea 6:6). אמת (from אמנת), continuance, a standing to one's promises, and not falsifying just expectations; thus fidelity, πίστις, in the interrelated sense of fides and fidelitas. These two states of mind and of conduct are here contemplated as moral powers (Psalm 61:8; Psalm 43:3), which are of excellent service, and bring precious gain; and 4b shows that their ramification on the side of God and of men, the religious and the moral, remains radically inseparable. The suffix ם does not refer to the doctrine and the precepts, but to these two cardinal virtues. If the disciple is admonished to bind them about his neck (vid., Proverbs 1:9, cf. Proverbs 3:22), so here reference is made, not to ornament, nor yet to protection against evil influences by means of them, as by an amulet
(Note: Fleischer is here reminded of the giraffe in the Jardin des Plantes, the head of which was adorned by its Arabic keeper with strings and jewels, the object of which was to turn aside the ‛ain [the bad, mischievous look] from the precious beast.)
(for which proofs are wanting), but to the signet which was wont to be constantly carried (Genesis 38:18, cf. Song 8:6) on a string around the neck. The parallel member 3c confirms this; 3b and 3c together put us in mind of the Tephillim (phylacteries), Exodus 13:16; Deuteronomy 6:8; Deuteronomy 11:18, in which what is here a figure is presented in external form, but as the real figure of that which is required in the inward parts. לוּח (from לוּח, Arab. l'ah, to begin to shine, e.g., of a shooting star, gleaming sword; vid., Wetzstein, Deutsch. morgenl. Zeitschr. xxii. 151f.) signifies the tablet prepared for writing by means of polish; to write love and fidelity on the tablet of the heart, is to impress deeply on the heart the duty of both virtues, so that one will be impelled to them from within outward (Jeremiah 31:33).

Mercy - Mercy denotes all benignity, charity, and readiness to do good to others: truth or faithfulness respects all those duties which we owe to God or man, which we have special obligation from the rules of justice. Bind them - Like a chain, wherewith persons adorn their necks. Table - In thy mind and heart, in which all God's commands are to be received and engraven.