O God, my heart is fixed. Though I have many wars to disturb me, and many cares to toss me to and fro, yet I am settled in one mind and cannot be driven from it. My heart has taken hold and abides in one resolve.

Awake, psaltery and harp. As if he could not be content with voice alone, but must use the well tuned strings, and communicate to them something of his own liveliness.

I will praise thee, O LORD, among the people. Whoever may come to hear me, devout or profane, believer or heathen, civilized or barbarian, I shall not cease my music.

For thy mercy is great above the heavens, and therefore there must be no limit of time, or place, or people, when that mercy is to be extolled. As the heavens over arch the whole earth, and from above mercy pours down upon men, so shalt thou be praised everywhere beneath the sky.

Be thou exalted, O God, above the heavens: and thy glory above all the earth. Let thy praise be according to the greatness of thy mercy. Ah, if we were to measure our devotion thus, with what ardour should we sing! The whole earth with its overhanging dome would seem too scant an orchestra, and all…

That thy beloved may be delivered: save with thy right hand, and answer me. Let my prayer avail for all the beloved ones. Sometimes a nation seems to hang upon the petitions of one man. With what ardour should such an one pour out his soul! David does so here.

God hath spoken in his holiness. Aforetime the Lord had made large promises to David, and these his holiness had guaranteed. The divine attributes were pledged to give the son of Jesse great blessings; there was no fear that the covenant God would run back from his plighted word. I will rejoice.

Gilead is mine. Thankful hearts dwell upon the gifts which the Lord has given them, and think it no task to mention them one by one. Manasseh is mine. I have it already, and it is to me the token and assurance that the rest of the promised heritage will also come into my possession in due time.

Moab is my washpot. This nation had shown no friendly spirit to the Israelites, but had continually viewed them as a detested rival, therefore they were to be subdued and made subject to David's throne. He claims by faith the victory, and regards his powerful enemy with contempt.

Faith leads on to strong desire for the realization of the promise, and hence the practical question, Who will bring me into the strong city? who will lead me into Edom? The difficulty is plainly perceived.

Wilt not thou, O God, who hast cast us off? This is grand faith which can trust the Lord even when he seems to have cast us off. Some can barely trust him when he pampers them, and yet David relied upon him when Israel seemed under a cloud and the Lord had hidden his face.

Give us help from trouble: for vain is the help of man. This prayer has often fallen from the lips of men who have been bitterly disappointed by their fellows, and it has also been poured out unto the Lord in the presence of some gigantic labour in which mortal power is evidently of no avail.

God's help shall inspire us to help ourselves. Faith is neither a coward nor a sluggard: she knows that God is with her, and therefore she does valiantly; she knows that he will tread down her enemies, and therefore she arises to tread them down in his name.

O God, my heart is fixed. The wheels of a chariot revolve, but the axletree turns not; the sails of a mill move with the wind, but the mill itself moves not; the earth is carried round its orbit, but its centre is fixed.

With reference to this passage the Talmud says, "A cithern used to hang above David's bed; and when midnight came the north wind blew among the strings, so that they sounded of themselves; and forthwith he arose and busied himself with the Torah until the pillar of the dawn ascended." Rashi…

For thy mercy is great, etc. His mercy is great—that mercy sung of lately . It is "from above the heavens" (Mymv-lem); i.e., coming down to us as do drops of a fertilizing shower; even as the "Peace on earth", of Lu 2:14, was first "peace in heaven" (Lu 19:38).—Andrew A. Bonar.

That thy beloved may be delivered, etc. The church is the Lord's "beloved", or the incorporation, more loved than anything else in the world, therefore here called, "Thy beloved." Because the church is God's beloved, the care of it should be most in our mind, and the love of the preservation of it…

God hath spoken the word of assurance. This refers to all the words in which the land of their inheritance was defined, especially Ge 15:18 Ex 23:31 De 11:24, and that remarkable prediction concerning the perpetuity of David's line, 2Sa 7:1-17, which must have made a deep impression on his mind.

Ephraim also is the strength of mine head. As Ephraim was the most populous of all the tribes, he appropriately terms it the strength of his head, that is, of his dominions.—John Calvin.

Moab, who had enticed Israel to impurity, is made a vessel for its purifying. Edom, descendant of him who despised his birthright, is deprived of his independence;—for "flinging a shoe" was a sign of the transference of a prior claim on land. Ru 4:7.—William Kay. Moab is my washpot.

The strong city built on the rock, even man's hardened heart, stronger and more stony than the tomb, he had conquered and overcome; and in him and his might are his people to carry on his warfare, and to cast down all the strongholds of human pride, and human stubbornness, and human…

Wilt not thou, O God? His hand shall lead him even to Petra, which seems unapproachable by human strength. That marvellous rock city of the Edomites is surrounded by rocks some of which are three hundred feet high, and a single path twelve in width leads to it.

Give us help from trouble, etc. He who would have God's help in any business, must quit confidence in man's help; and the seeing of the vanity of man's help must make the believer to trust the more unto, and expect the more confidently God's help, as here is done.