Set a watch, O Jehovah! upon my mouth. As David was liable to be hurt at the unbridled and unprincipled rage of his enemies, so as to be tempted to act in a manner that might not be justifiable, he prays for divine direction, and not that he might be kept back from manual violence merely, but that his tongue might be restrained from venting reproach, or words of complaint. Even persons of the most self-possessed temper, if unwarrantably injured, will some -- times proceed to make retaliation, through their resenting the unbecoming conduct of their enemies. David prays accordingly that his tongue might be restrained by the Lord from uttering any word which was out of joint. Next he seeks that his heart be kept back from every mischievous device that might issue in revenge. The words added -- that I may not eat of their delicacies, are to be understood figuratively, as a petition that he might not be tempted by the prosperity which they enjoyed in sin to imitate their conduct. The three things mentioned in the context are to be connected; and it may be advisable to consider each of them more particularly. Nothing being more difficult than for the victims of unjust persecution to bridle their speech, and submit silently and without complaint to injuries, David needed to pray that his mouth might be closed and guarded -- that the door of his mouth might be kept shut by God, as one who keeps the gate watches the ingress and egress -- ntsrh, nitsrah, being the imperative of the verb, rather than a noun. He next subjoins that God would not incline his heart to an evil thing; for dvr, dabar, is here, as in many other places, used to signify a thing. Immediately after he explains himself to mean, that he would not desire to strive with them in wickedness, and thus make himself like his enemies. Had that monk of whom Eusebius makes mention duly reflected upon this resolution of David, he would not have fallen into the silly fallacy of imagining that he had shown himself the perfect scholar by observing silence for a whole term of seven years. Hearing that the regulation of the tongue was a rare virtue, he betook himself to a distant solitude, from which he did not return to his master for seven years; and being asked the cause of his long absence, replied that he had been meditating upon what he had learned from this verse. It would have been proper to have asked him at the same time, whether during the interim he had thought none, as well as spoken none. For the two things stand connected the being silent, and the being free from the charge of evil thoughts. It is very possible that although he observed silence, he had many ungodly thoughts, and these are worse than vain words. We have simply alluded in passing to this foolish notion, as what may convince the reader of the possibility of persons running away with a word torn from its connection, and overlooking the scope of the writer. In committing himself to the guidance of God, both as to thoughts and words, David acknowledges the need of the influence of the Spirit for the regulation of his tongue and of his mind, particularly when tempted to be exasperated by the insolence of opposition. If, on the one hand, the tongue be liable to slip and too fast of utterance, unless continually watched and guarded by God; on the other, there are disorderly affections of an inward kind which require to be restrained. What a busy workshop is the heart of man, and what a host of devices is there manufactured every moment! If God do not watch over our heart and tongue, there will confessedly be no bounds to words and thoughts of a sinful kind, -- so rare a gift of the Spirit is moderation in language, while Satan is ever making suggestions which will be readily and easily complied with, unless God prevent. It need not seem absurd to speak of God inclining our hearts to evil, since these are in his hand, to turn them whithersoever he willeth at his pleasure. Not that he himself prompts them to evil desires, but as according to his secret judgments he surrenders and effectually gives over the wicked to Satan's tyranny, he is properly said to blind and harden them. The blame of their sins rests with men themselves, and the lust which is in them; and, as they are carried out to good or evil by a natural desire, it is not from any external impulse that they incline to what is evil, but spontaneously and of their own corruption. I have read -- to work the works of iniquity; others read -- to think the thoughts of iniquity. The meaning is the same, and it is needless to insist upon the preference to be given. By mnmym, manammim, translated delicacies, is meant the satisfaction felt by the ungodly when their sins are connived at through the divine forbearance. While their insolence in such a case becomes more presumptuous, even the Lord's people are in danger of being deceived by the prosperity they see enjoying, and to take liberties themselves. David had reason therefore to pray for the secret restraints of the Holy Spirit, that he might be kept from feasting on their delicacies; that is, being intoxicated into license or sinful pleasure through anything debasing, flattering, or agreeable in outward circumstances.

Set a watch, O Lord, before my mouth - That I may not say anything rashly, unadvisedly, improperly. Compare Psalm 39:1. The prayer here is, that God would guard him from the temptation to say something wrong. To this he seems to have been prompted by the circumstances of the case, and by the advice of those who were with him. See introduction to the psalm. Compare the notes at Psalm 11:1.
Keep the door of my lips - That my lips or mouth may not open except when it is proper and right; when something good and true is to be said. Nothing can be more proper than "this" prayer; nothing more desirable than that God should keep us from saying what we ought not to say.

Set a watch, O Lord, before my mouth - While there are so many spies on my actions and words, I have need to be doubly guarded, that my enemies may have no advantage against me. Some think the prayer is against impatience; but if he were now going to Gath, it is more natural to suppose that he was praying to be preserved from dishonoring the truth, and from making sinful concessions in a heathen land; and at a court where, from his circumstances, it was natural to suppose he might be tempted to apostasy by the heathen party. The following verse seems to support this opinion.

Set a watch, O LORD, before my mouth; (c) keep the door of my lips.
(c) He desires God to keep his thoughts and ways either from thinking or executing vengeance.

Set a watch, O Lord, before my mouth,.... While praying, as Jarchi and Kimchi; that he might not utter any rash, unguarded, and unbecoming word; but take and use the words which God gives, even the taught words of the Holy Ghost; or lest, being under affliction and oppression, he should speak unadvisedly with his lips, and utter any impatient murmuring and repining word against God; or express any fretfulness at the prosperity of the wicked, or speak evil of them; especially of Saul, the Lord's anointed, for the ill usage of him;
keep the door of my lips; which are as a door that opens and shuts: this he desires might be kept as with a bridle, especially while the wicked were before him; lest he should say anything they would use against him, and to the reproach of religion; and that no corrupt communication, or any foolish and filthy talk, or idle and unprofitable words, might proceed from them. The phrase signifies the same as the other; he was sensible of his own inability to keep a proper watch and guard over his words, as was necessary, and therefore prays the Lord to do it; see Psalm 39:1.

The prayer now begins to be particularized, and that in the first instance as a petition fore the grace of silence, calling to mind old Davidic passages like Psalm 39:2; Psalm 34:14. The situation of David, the betrayed one, requires caution in speaking; and the consciousness of having sinned, not indeed against the rebels, but against God, who would not visit him thus without his deserving it, stood in the way of any outspoken self-vindication. In pone custodiam ori meo שׁמרה is ἅπ. λεγ., after the infinitive form דּבקה, עזבה, עצמה. In Psalm 141:3 דּל is ἅπ. λεγ. for דּלת; cf. "doors of the mouth" in Micah 7:5, and πύλαι στόματος in Euripides. נצּרה might be imper. Kal: keep I pray, with Dag. dirimens as in Proverbs 4:13. But נצר על is not in use; and also as the parallel word to שׁמרה, which likewise has the appearance of being imperative, נצּרה is explicable as regards its pointing by a comparison of יקּהה in Genesis 49:10, דּבּרה in Deuteronomy 33:3, and קרבה in Psalm 73:28. The prayer for the grace of silence is followed in Psalm 141:4 by a prayer for the breaking off of all fellowship with the existing rulers. By a flight of irony they are called אישׁים, lords, in the sense of בּני אישׁ, Psalm 4:3 (cf. the Spanish hidalgos = hijos d'algo, sons of somebody). The evil thing (רע