7 proclaiming aloud your praise and telling of all your wonderful deeds.
981 Sing to the Lord a new song, for he has done marvelous things; his right hand and his holy arm have worked salvation for him.
(Read Psalm 98:1-3)
A song of praise for redeeming love is a new song, a mystery hidden from ages and generations. Converts sing a new song, very different from what they had sung. If the grace of God put a new heart into our breasts, it will put a new song into our mouths. Let this new song be sung to the praise of God, in consideration of the wonders he has wrought. The Redeemer has overcome all difficulties in the way of our redemption, and was not discouraged by the services or sufferings appointed him. Let us praise him for the discoveries made to the world of the work of redemption; his salvation and his righteousness fulfilling the prophecies and promises of the Old Testament. In pursuance of this design, God raised up his Son Jesus to be not only a Light to lighten the Gentiles, but the glory of his people Israel. Surely it behoves us to inquire whether his holy arm hath gotten the victory in our hearts, over the power of Satan, unbelief, and sin? If this be our happy case, we shall exchange all light songs of vanity for songs of joy and thanksgiving; our lives will celebrate the Redeemer's praise.
Matthew Henry's Commentary on Psalm 26:7
David, in this psalm, appeals to God touching his integrity.
David here, by the Spirit of prophecy, speaks of himself as a type of Christ, of whom what he here says of his spotless innocence was fully and eminently true, and of Christ only, and to Him we may apply it. We are complete in him. The man that walks in his integrity, yet trusting wholly in the grace of God, is in a state of acceptance, according to the covenant of which Jesus was the Mediator, in virtue of his spotless obedience even unto death. This man desires to have his inmost soul searched and proved by the Lord. He is aware of the deceitfulness of his own heart; he desires to detect and mortify every sin; and he longs to be satisfied of his being a true believer, and to practise the holy commands of God. Great care to avoid bad company, is both a good evidence of our integrity, and a good means to keep us in it. Hypocrites and dissemblers may be found attending on God's ordinances; but it is a good sign of sincerity, if we attend upon them, as the psalmist here tells us he did, in the exercise of repentance and conscientious obedience. He feels his ground firm under him; and, as he delights in blessing the Lord with his congregations on earth, he trusts that shortly he shall join the great assembly in heaven, in singing praises to God and to the Lamb for evermore.