This psalm is described as a "psalm of David," and it bears internal evidence that it was composed by him, as it contains first, a prayer for deliverance from enemies Psalm 64:1-6; and second, a confident expectation of deliverance, Psalm 64:7-10; a form of structure found in many of the psalms written by David. It is addressed, or dedicated, as many others are, "To the chief Musician." This fact shows that it was not designed as an expression of mere private feeling, but was intended to be employed in the worship of God. See the notes at the Introduction to Psalm 4:1-8.
The occasion on which this psalm was composed is unknown. In its general structure and character, it bears a strong resemblance to Psalm 58:1-11. Indeed, many of the expressions in the two psalms are the same, and it would seem probable that it was composed with reference to the same occasion, or that the circumstances in the two cases were so similar as to make the same expressions in the main appropriate. The occasion may have been, either the times of persecution under Saul, or the rebellion of Absalom. Perhaps we may suppose, without impropriety, that the former psalm Psalm 58:1-11 was composed in the time of Saul, and this in the time of Absalom, and that the circumstances in the two eases were so similar, that the author found the same phraseology which he had used on the former occasion to be appropriate to his present position, or that his feelings were so identical now with what they were then, that he naturally expressed himself in substantially the same language.
The psalm, as observed above, is composed of two parts:
I. A prayer for deliverance from his enemies, with a description of their character, Psalm 64:1-6.
II. An expression of confident expectation that his prayer would be answered, and that God would interpose in his behalf, Psalm 64:7-10.

The psalmist prays for preservation from the wicked, Psalm 64:1, Psalm 64:2; whom he describes, Psalm 64:3-6; shows their punishment, Psalm 64:7, Psalm 64:8; and the effect that this should have on the godly, Psalm 64:9, Psalm 64:10.
The title, To the chief Musician, or conqueror, A Psalm of David. The Syriac says, "composed by David when warned by Gad the prophet, who said, Stay not in Masrob, because Saul seeks thy life." Some think it was composed by David when he was persecuted by Saul; or during the rebellion of Absalom. But Calmet thinks it is a complaint of the captives in Babylon.

INTRODUCTION TO PSALM 64
To the chief Musician, A Psalm of David. This psalm is applied by R. Obadiah to Haman and Mordecai. The enemy is Haman, the perfect man shot at is Mordecai; about whom Haman communed with his friends to lay snares for him, and searched diligently for occasions against him and his people, which issued in his own destruction. The ancient Midrash (y) of the Jews applies it to Daniel, when cast into the den of lions; and Jarchi supposes that David, by a spirit of prophecy, foresaw it, and prayed for him who was of his seed; and that everything in the psalm beautifully falls in with that account: Daniel is the perfect man aimed at; the enemy are the princes of Darius's court, who consulted against him, communed of laying snares for him, and gained their point, which proved their own ruin. But the psalm literally belongs to David, by whom it was composed. The Arabic versions call it a psalm of David, when Saul persecuted him; and the Syriac version refers it to the time when Gad said to him, abide not in the hold, 1-Samuel 22:5. He is the perfect man, who was upright and innocent as to what he was charged with in respect to Saul; who is the enemy, from the fear of whom he desires his life might be preserved; and who with his courtiers took counsel against him, and laid deep schemes to destroy him, but at last were destroyed themselves. Moreover, the psalm may very well be applied to the Messiah, the son of David, and who was his antitype, and especially in his sufferings: he is the perfect man in the highest sense; the Jews were the enemies that took counsel, and searched for occasions against him, and accomplished their designs in a good measure; for which wrath came upon them to the uttermost. The psalmist also may be very well thought to represent the church and people of God; who in all ages have had their enemies and their fears; against whom wicked men have devised mischief, and levelled their arrows of persecution; though no weapon formed against them shall prosper.
(y) Apud Jarchium & Yalkut Simeoni in loc.

(Psalm 64:1-6) Prayer for deliverance.
(Psalm 64:7-10) The destruction of the wicked, encouragement to the righteous.

invocation of Divine Protection against the Falseness of Men
Even Hilary begins the exposition of this Psalm with the words Psalmi superscriptio historiam non continet, in order at the outset to give up all attempt at setting forth its historical connection. The Midrash observes that it is very applicable to Daniel, who was cast into the lions' den by the satraps by means of a delicately woven plot. This is indeed true; but only because it is wanting in any specially defined features and cannot with any certainty be identified with one or other of the two great periods of suffering in the life of David.