This psalm is asserted in the title to have been composed by David, and there is nothing in its contents contrary to this supposition, as there is nothing in it that would lead us necessarily to ascribe it to him. The contents of the psalm indeed correspond with the facts of his history, and with the recollections of his early life as a shepherd; but it is such as might have been composed by anyone who had been, and in fact by anyone though he had not been, a shepherd, as the images in it are such as are common in all poetry. Still, there is nothing to lead us to doubt that it was written by David.
It is wholly uncertain on what occasion the psalm was composed, since there are in the psalm no historical references, no indications of time, and no allusions to any circumstances in the life of the author. It is impossible even to determine whether it was composed in a time of prosperity or adversity; whether when the author was persecuted, or when he was prosperous and triumphant. The only apparent allusion to any circumstance of the poet's life is in Psalm 23:6, where he says, as the crowning joy which he anticipated, that he would "dwell in the house of the Lord forever," from which it has been inferred by some that he was then in exile. But this allusion is of too general a character to justify this inference with certainty. Such a hope might be expressed by anyone in any circumstances, as the highest desire of a pious heart. Kimchi supposes that the psalm was composed by David in the wilderness of Hareth 1-Samuel 22:5; and that it pertained to the people of Israel, and to their return from exile. But this is mere conjecture. The Aramaic Paraphrase applies the psalm to the Hebrew people when delivered from captivity and exile, as a song of triumph on their return to their own land. Rudinger, and John D. Michaelis, suppose that it refers to the time when David had obtained a complete victory over all his enemies - when the rebellion of Absalom was quelled, when he was seated quietly on throne. Probably, if we are to to fix a time, it was at that period of life - an advanced period - when the recollection of the merciful interpositic of God in his behalf so often would suggest the brightest image of his earlier years, the watchful care which he as a shepherd had extended over his own flock - a care which God had now extended over him in the perils of his own life. Still, all this is no more than conjecture.
The psalm has always been regarded as one of exquisite beauty. The main subject is the watchful care which God had extended over the author, and the consequent assurance which he felt that God would still watch over him, and supply all his need. The leading thought - the essential idea - is, his full belief that God would provide for him, and that he would never be left to want. This is the thought with which the psalm commences: "The Lord is my shepherd; I shall not want:" and this thought is carried through the psalm. It is illustrated by two facts or images:
(a) That God was his shepherd; that He had always manifested toward him (David) the care which a shepherd takes of his flock, Psalm 23:1-3; and
(b) That God had prepared a table before him (David) in the very presence of his enemies, or that he had abundantly led for him in their very sight, when they were endeavoring to destroy him - thus giving him the assurance that God never would leave him, Psalm 23:5.
The psalm, therefore, may be regarded as consisting of two main parts:
I. The general subject of the psalm - the confidence of the author in God - the assurance that he would always so provide for him that he would not want, Psalm 23:1.
II. The grounds or reasons for this confidence, Psalm 23:2-6. These are twofold:
(1) An argument derived from the care of God over him as a shepherd, Psalm 23:2-4.
(a) The statement of the fact, Psalm 23:2-3.
(b) The argument, Psalm 23:4. From his experience of the divine care in the past, he says that he would not be afraid even to descend into the valley of death.
(2) an argument derived from the fact that God had provided for him in the very presence of his enemies, Psalm 23:5-6.
(a) The statement of the fact; or a reference to his life, during which God had shown the same care and goodness as if He had spread a table for him even in the sight of his enemies, Psalm 23:5.
(b) The confident assurance, derived from that fact, that God would follow him with goodness and mercy all the days of his life; that his future course would be as if he were always to dwell in the house of the Lord, Psalm 23:6.

The Lord is the Pastor of his people; therefore it may be inferred that they shall not want, Psalm 23:1. How he guides, feeds, and protects them, Psalm 23:2, Psalm 23:3. Even in the greatest dangers they may be confident of his support, Psalm 23:4. His abundant provision for them, Psalm 23:5. The confidence they may have of his continual mercy, and their eternal happiness, Psalm 23:6.
There is nothing particular in the title; it is simply attributed to David; but as it appears to be a thanksgiving of the Israelites for their redemption from the Bablylonish captivity, it cannot with propriety be attributed to David. Some think it was written by David in his exile, which is not likely; others, that he penned it when he was finally delivered from the persecution of Saul. I rather incline to the opinion that it was written after the captivity. The Chaldee seems to suppose that it was written to celebrate the goodness of God to the Israelites in the desert. It is a truly beautiful Psalm. Supposing it to have been written after the captivity, we see,
1. The redeemed captives giving thanks to God for their liberty.
2. Acknowledging that God had brought back their lives from the grave.
3. They represent themselves in Judea as a flock in an excellent pasture.
4. They declare that from the dangers they have passed through, and from which God had delivered them, they can have no fear of any enemy.
5. They conclude, from what God has done for them, that his goodness and mercy shall follow them all their days.
6. That they shall no more be deprived of God's worship, but shall all their days have access to his temple.

INTRODUCTION TO PSALM 23
A Psalm of David. Thus psalm was written by David, either when he was in distressed circumstances, being persecuted by Saul, and was in the forest of Hareth, 1-Samuel 22:5; as some think (r); wherefore he comforts himself with the Lord's being his shepherd, so that he should not want; nor would he fear, was he in worse circumstances than he at present was; or rather, when he was settled upon the throne of Israel, and in the most prosperous and flourishing state of his reign, as the latter part of the psalm shows; he speaks not in his own person only, but in the name of all believers; for Christ, who is the shepherd spoken of, is a common shepherd to all the saints, who are all the sheep of his pasture, as well as David; and the prophet here makes use of similes very familiar with him; he having been a shepherd himself, and knew what it was to do all the parts of that office, which are herein expressed; and very pertinently does this psalm follow the former; for as there Christ is prophesied of as laying down his life for the sheep, as the good shepherd does; and of his being brought again from the dead, as the great shepherd of the sheep, as Christ has been; so here of his performing his office as such, in all its parts, to the great comfort, refreshment, and safety of his people.
(r) Jarchi & Kimchi.

Confidence in God's grace and care.

Praise of the Good Shepherd
The arrangement, by which a Psalm that speaks of a great feast of mercy prepared for mankind is followed by a Psalm that praises Jahve as the Shepherd and Host of His own people, could not possibly be more sensible and appropriate. If David is the author, and there is no reason for doubting it, then this Psalm belongs to the time of the rebellion under Absolom, and this supposition is confirmed on every hand. It is like an amplification of Psalm 4:8; and Psalm 3:7 is also echoed in it. But not only does it contain points of contact with this pair of Psalm of the time mentioned, but also with other Psalm belonging to the same period, as Psalm 27:4, and more especially Psalm 63:1-11, which is said to have been composed when David had retreated with his faithful followers over Kidron and the Mount of Olives into the plains of the wilderness of Judah, whither Hushai sent him tidings, which counselled him to pass over Jordan with all possible haste. It is characteristic of all these Psalm, that in them David years after the house of God as after the peculiar home of his heart, and, that all his wishes centre in the one wish to be at home again. And does not this short, tender song, with its depth of feeling and its May-like freshness, accord with David's want and wanderings to and fro at that time?
It consists of two hexastichs with short closing lines, resembling (as also in Isaiah 16:9-10) the Adonic verse of the strophe of Sappho, and a tetrastich made up of very short and longer lines intermixed.