7 Yahweh is my strength and my shield. My heart has trusted in him, and I am helped. Therefore my heart greatly rejoices. With my song I will thank him.
*Minor differences ignored. Grouped by changes, with first version listed as example.
The Lord is my strength - See the notes at Psalm 18:1.
And my shield - See the notes at Psalm 3:3. Compare Psalm 33:20; Psalm 59:11; Psalm 84:9; Psalm 89:18; Genesis 15:1.
My heart trusted in him - I trusted or confided in him. See Psalm 13:5.
And I am helped - I have found the assistance which I desired.
Therefore my heart greatly rejoiceth - I greatly rejoice. I am happy. He had found the assurance of the divine favor which he desired, and his heart was glad.
And with my song will I praise him - I will sing praises to Him. Compare Psalm 22:25.
The Lord is my strength - I have the fullest persuasion that he hears, will answer, and will save me.
The Lord is my strength,.... That is, the author both of natural and spiritual strength; that gave him strength of body, and fortitude of mind, to bear up under all the exercises he was tried with; the strength of his life, spiritual and temporal, and of his salvation; the strength of his heart under present distresses, and who he knew would be so in the hour of death, when his heart and strength would fail;
and my shield; to protect and defend him; as were the love, power, and faithfulness of God, and the Lord Jesus Christ, his power and fulness, his blood, righteousness, and salvation;
my heart trusted in him; in the Lord as his strength and shield; not in any creature, nor in his own strength and righteousness; but in the Lord God, in whom are righteousness and strength: and it is plain he did not trust in his own heart, since his heart trusted in the Lord; and which shows that his trust was an hearty one, his faith was a faith unfeigned, he believed with the heart unto righteousness;
and I am helped: this was the fruit of his trust, even a gracious experience of divine assistance: saints are helpless in themselves, and are also as to the help of man; God is the only helper of them; he helps them out of all their troubles; in whatsoever he calls them unto, and to what they want; and the help he affords is sometimes quick, and always seasonable; and sometimes by means, and sometimes without them;
therefore my heart greatly rejoiceth; that is, in the Lord, the ground of which was the help he had from him; and this joy was very great, a joy unspeakable, and full of glory; it was not carnal, but spiritual, a heart joy, joy in the Holy Ghost;
and with my song will I praise him; praise is due to God, what glorifies him, and is acceptable to him; it becomes the saints, is comely for them, and it is pleasant work to them, when grace is in exercise; see Psalm 69:30; this may be understood of one of his songs, and one of the best of them, and of one better than this, as a Jewish writer (u) observes.
(u) R. Moseh in Aben Ezra in loc.
The repetition of "heart" denotes his sincerity.
I am helped - He speaks of it as past, because God assured him by his spirit, that he had heard and accepted his prayers.
*More commentary available at chapter level.