This psalm purports to be "A Psalm of David," and there is no reason to doubt that it was composed by him. On what occasion it was composed is now unknown, and there is nothing in the psalm itself to enable us to decide. Some have supposed that it was written in view of the persecution of David by Saul; and others, that it was in view of the rebellion of Absalom. There is nothing in the psalm, however, which shows that it has any spectral reference to those persecutions or troubles; nothing which might not have been uttered if those troubles had never occurred. All the expressions in the psalm are of a general character, and seem rather to refer to a prevailing state of iniquity than to any particular manifestation of wickedness as pertaining to the psalmist himself.
The psalm undoubtedly does refer to prevailing iniquity, and it is not difficult to determine to what form of iniquity it refers. It was a general failure of fidelity among good men; a general withdrawal from active duties of such men as had before been found faithful; a lack of that firmness and zeal which it was proper to expect from those who professed to be good men. Particularly, it refers to prevailing modes of speech among those from whom it was right to expect better things: a condition in which there was a lack of seriousness and sincerity in conversation; in which flattery abounded; in which double meanings in conversation were common; in which promises solemnly made could not be relied on; and in which there was, in consequence, great wrong done to the poor and the unsuspecting - those who, on account of their ignorance and their unsuspicious nature, were greatly injured by putting confidence in such promises and assurances. In this state of things the psalmist felt that it was proper to call on God to protect those who were exposed to such wrongs.
The psalm, therefore, is composed of these parts:
I. A statement of the prevailing condition of things, as a reason why it was proper for God to interpose, Psalm 12:1-2.
II. The fact that the Lord would interpose in such cases, and would cut off this class of persons, Psalm 12:3-5.
III. The strong contrast between the words of the Lord and the language which was then in prevalent use, Psalm 12:6. The words of the Lord were pure; pure as silver tried by the severest tests of fire.
IV. A deep conviction on the part of the psalmist that God would be the protector of those who were thus exposed to injury and wrong; particular y he would keep them from the purposes of such a generation forever, Psalm 12:7.
V. The closing verse, "The wicked walk on every side, when the vilest men are exalted" Psalm 12:8, seems to be but the carrying out of the idea of the divine protection in the psalm: "Let the wicked walk about, therefore, on every side when vile men are exalted to power, for God is the protector of his people, and all such men are under his control." Or it may be the statement of a fact that wickedness did abound, or that people seemed to be unrestrained when wicked men were in power, though with the idea that God saw them, and would so check and restrain them that the injured and the wronged would be protected.
The title to the psalm - "To the chief Musician upon Sheminith" - is the same as that of the sixth Psalm, except that the words "On Neginoth," used there, are here omitted. See the note at that psalm.

The psalmist, destitute of human comfort, craves help from God, Psalm 12:1; gives the character of those who surrounded him, and denounces God's judgments against them, Psalm 12:2-5; confides in the promises of God, and in his protection of him and all good men, Psalm 12:6-8.
The inscription to this Psalm is: To the chief Musician upon Sheminith, A Psalm of David. See on the title of Psalm 6:1-10 (note): The Arabic has "Concerning the end (of the world which shall happen) on the eighth day. A prophecy relative to the Advent of the Messiah." Some think that this Psalm was made when Doeg and the Ziphites betrayed David to Saul, see 1 Samuel 22 and 23; but it is most likely that was written during the Babylonish captivity.

INTRODUCTION TO PSALM 12
To the chief Musician upon Sheminith, a Psalm of David.
The word "sheminith" is used in the title of Psalm 6:1, and signifies "eighth"; and intends either the eighth note, to which the psalm was sung, or rather the harp of eight chords, to which it was set, as the Targum and Jarchi interpret it. Some Jewish writers (y) understand it of the times of the Messiah; and the Syriac version entitles the psalm,
"an accusation of the wicked, and a prophecy concerning the coming of the Messiah:''
and the Arabic version says, it is concerning the end of the world, which shall be in the eighth day; and concerning the coming of the Messiah: but Arnobius interprets it of the Lord's day.
(y) Sepher Lekach Shechachah apud Caphtor, fol. 64. 1. & Ceseph Misnah in Maimon. Hilch. Teshuvah, c. 9.

The psalmist begs help of God, because there were none among men whom he durst trust.

Lament and Consolation in the Midst of Prevailing Falsehood
Psalm 11:1-7 is appropriately followed by Psalm 12:1-8, which is of a kindred character: a prayer for the deliverance of the poor and miserable in a time of universal moral corruption, and more particularly of prevailing faithlessness and boasting. The inscription: To the Precentor, on the Octave, a Psalm of David points us to the time when the Temple music was being established, i.e., the time of David - incomparably the best age in the history of Israel, and yet, viewed in the light of the spirit of holiness, an age so radically corrupt. The true people of Jahve were even then, as ever, a church of confessors and martyrs, and the sighing for the coming of Jahve was then not less deep than the cry "Come, Lord Jesus!" at the present time.
This Psalm 12:1-8 together with Psalm 2:1-12 is a second example of the way in which the psalmist, when under great excitement of spirit, passes over into the tone of one who directly hears God's words, and therefore into the tone of an inspired prophet. Just as lyric poetry in general, as being a direct and solemn expression of strong inward feeling, is the earliest form of poetry: so psalm-poetry contains in itself not only the mashal, the epos, and the drama in their preformative stages, but prophecy also, as we have it in the prophetic writings of its most flourishing period, has, as it were, sprung from the bosom of psalm-poetry. It is throughout a blending of prophetical epic and subjective lyric elements, and is in many respects the echo of earlier psalms, and even in some instances (as e.g., Isaiah 12:1-6; Habakkuk 3:1) transforms itself into the strain of a psalm. Hence Asaph is called החזה in 2-Chronicles 29:30, not from the special character of his Psalm, but from his being a psalmist in general; for Jeduthun has the same name given to him in 2-Chronicles 35:15, and נבּא in 1-Chronicles 25:2. (cf. προφητεύειν, Luke 1:67) is used directly as an epithet for psalm-singing with accompaniment-a clear proof that in prophecy the co-operation of a human element is no less to be acknowledged, that the influence of a divine element in psalm-poesy.
The direct words of Jahve, and the psalmist's Amen to them, form the middle portion of this Psalm-a six line strophe, which is surrounded by four line strophes.