Verse 1
Psalms 101:1. I will sing of mercy and judgment — It is doubtful whether David, in thus determining to make mercy and judgment the subjects of his song, intended the mercy which God had shown him, and the judgment which God had executed on his enemies; or the mercy and judgment which he himself purposed to dispense in his dominions, according to the different characters of his subjects. Possibly he might include both, and the purport of his resolution may be this: I will praise thee, O Lord, as for all thy other excellences, so particularly for those two royal perfections of mercy and justice, or judgment, which thou hast so eminently discovered in the government of the world, and of thy people Israel; and I will make it my care to imitate thee, as in other things, so especially in these virtues, which are so necessary for the discharge of my trust, and the good government of thy and my people. “The Psalm,” says Dr. Dodd, “has a double reference, and describes the manner in which David intended to act toward his subjects, under their different denominations, as they were good or bad ones. Toward the faithful in the land he would show חסד, chesed, benignity, and favour; toward the wicked, and such as obstinately violated the laws, he would exercise משׁפשׂ, mishpat, judgment, as he would judge and punish them according to their deeds. And as this was his fixed purpose, he consecrated this song to God; appealing hereby to him for the sincerity of his intention, to make mercy and judgment the great rules of his administration; and agreeably hereto it is observed of him, that he executed justice and judgment to all the people, 2 Samuel 8:15.”

Verse 2
Psalms 101:2. I will behave myself wisely in a perfect way — I will manage my affairs with wisdom and integrity; which are the two chief qualifications requisite for all men, and peculiarly necessary in princes, whose example is wont to have great influence on the morals of their people, and who can with no dignity nor consistency punish the crimes of others, if they be guilty of the same crimes themselves. O, when wilt thou come to me? —

And be with me to assist me to execute this my purpose. God is often said, in Scripture, to come to men when he fulfils a promise to them, confers a favour upon them, peculiarly assists them, or is, in an especial manner, present with them. David, having declared it to be his resolution to set his court and kingdom an example of true wisdom and unshaken integrity, shows, in these words, the sense he had of his need of a peculiar visitation of divine grace, to enable him to put his resolution in practice, and accordingly expresses the passionate desire which he had for it in these words. I will walk within my house — I will conduct myself in my family and court, as well as in my public administration of the affairs of my kingdom, with a perfect heart — Sincerely intending and desiring to please and glorify God, and to set before the members of my family, and all my subjects, an example worthy of their imitation. This clause adds weight to the former. He determines not only to walk in a perfect or right way, which a man might do for politic reasons, or with an evil design; but to do so with an upright, honest heart, which is most acceptable to God.

Verse 3-4
Psalms 101:3-4. I will set no wicked thing before mine eyes — Namely, to look upon it with approbation, or design to practise, countenance, or tolerate it. If any ungodly or unjust thing be suggested to me, whatsoever specious pretences it may be covered with, as some reason of state or worldly advantage, I will cast it out of my mind and thoughts with abhorrence, so far will I be from putting it in execution. I hate the work of them that turn aside — From God, and from his laws. It shall not cleave to me —

Namely, such work, or the contagion of such examples. I will neither imitate nor endure such works nor such workers. A froward heart — A man of a corrupt mind and wicked life; shall depart from me — Shall be turned out of my court, lest he should infect the rest of my family, or be injurious, or an occasion of offence to my people. I will not know a wicked person — I will not own nor countenance such a one, but will keep all such at a distance.

Verse 5-6
Psalms 101:5-6. Whoso privily slandereth his neighbour — Such as by secret and false informations, and accusations of others, seek to gain my favour, and to advance themselves by the ruin of others; him will I cut off — From my family and court. Him that hath a high look, &c. — Those who think highly of themselves, and look down with contempt upon others, or treat them with insolence; or, whose insatiable covetousness and ambition make them study their own advancement more than the public good; will not I suffer — In my house nor among my servants. Mine eyes shall be upon the faithful — I will endeavour to find out, and will favour and encourage, men of truth, justice, and integrity, men of religion and virtue, who will be faithful, first to God, and then to me and to my people; that they may dwell with me — Hebrew, לשׁבת, lashebeth,, to sit, abide, or converse with me, in my house, and counsels, and public administrations. These he would use as his familiars and friends, employ them in the domestic services of his palace, and advance them to public offices and stations in his kingdom. He that walketh in a perfect way — In the way of God’s precepts, which are pure and perfect; he shall serve me — In domestic and public employments.

Verse 7
Psalms 101:7. He that worketh deceit — That uses any frauds or subtle artifice to deceive, abuse, or wrong any of my people; shall not dwell within my house — Though he may insinuate himself into my family, yet, as soon as he is discovered, he shall be turned out of it. He that telleth lies — Either to defend and excuse the guilty, or to betray the innocent; shall not tarry in my sight — I will certainly and immediately banish him from my presence.

Verse 8
Psalms 101:8. I will early destroy all the wicked — That is, all that are discovered and convicted; the law shall have its course against them; and incorrigible offenders shall suffer as it directs. That I may cut off all wicked doers from the city of the Lord — “I will use my utmost diligence to reform the whole nation; but especially the place of my peculiar residence, which ought to be an example to the rest of my kingdom: taking care that all offenders be severely punished in the courts of justice; and, if there be no other remedy, cutting off those evil members, who have got an incurable habit of acting wickedly.” So Bishop Patrick. Dr. Chandler considers this last clause as an evident proof that David was now king over all Israel, and in possession of Jerusalem, styled by him the city of the Lord, because it was now the place where the Lord was peculiarly present, David having lodged the ark in the tabernacle prepared there for its reception. It is justly observed by the same judicious divine, that “this Psalm affords an admirable lesson for princes, to direct themselves in the administration of their affairs in public and private life. They should be the patrons of religion and virtue, and encourage them by their own example and practice. Those of their households, their servants, ministers, and particularly their favourites and friends, should be of unblameable characters, and, if possible, eminent for every thing that is excellent and praiseworthy. Subtle and fraudulent men, back-biters, and slanderers, and private informers against others, they should detest, and show the utmost marks of displeasure at them. They should maintain the honour of the laws, and impartially punish all transgressors against them; and, instead of indulging ease, and being engrossed and dissipated by pleasure and amusement, they should consecrate a just portion of their time to the public service, and promoting the real happiness of their people. Thus they will be indeed truly patriot kings, honoured of God and esteemed and beloved of men.”