My heart is fixed, O God, my heart is fixed: I will sing and give praise.
-Determination to praise God. Verse 7. My heart is fixed, O God, my heart is fixed - literally, prepared, established. The repetition emphasizes the steadfastness of his confidence of deliverance and the fixity of his resolution to praise (cf. Psalms 112:7-8).
Verse 8. Awake up, my glory - i:e., my soul (Psalms 16:9; Genesis 49:6).
Awake, psaltery and harp. These had slept in silence until David received the assurance of deliverance.
I myself will awake early - literally, more poetically, 'I will stir up the morning dawn.' I will waken it up, not it me. I will anticipate the sun in rising to bless God: implying zeal and unwearied earnestness in the Lord's service (Psalms 63:1; Psalms 78:34; Mark 1:35.
Verse 9. I will praise thee, O Lord, among the people - `the peoples' (cf. Psalms 18:49).
Verse 10. For thy mercy is great unto the heavens, and thy truth unto the clouds - (Psalms 36:5.; Psalms 103:11.) Those things which we wish to glorify we, extol to the skies, as the expression is. As God 'sends forth His mercy and His truth' from heaven to earth, so the recipients extol the greatness of His mercy and His truth unto the heavens. The greatness of God's mercy is as high as the heavens are above the earth.