So will I sing praise unto thy name for ever - As the result of this gracious interposition. Compare the notes at Isaiah 38:20. The meaning is, that he would do this constantly. It would be the regular business of his life.
That I may daily perform my vows - The solemn promises which I have made in my exile; the purposes which I have expressed to devote myself to thee. Or, the language may have been used in a more general sense, denoting that, as a religious man, the vows of God were constantly on him, or that he had pledged himself to serve God faithfully and always, and that he could better perform this duty at the tabernacle - in the place consecrated to public worship - than he could in exile. He desired, therefore, to be restored to the sanctuary, that he might keep up the performance of the daily duties of religion without interruption or hindrance. The whole psalm indicates a fervent desire to be engaged in the worship and service of God; a desire to be with Him and to enjoy His favor on earth; a confident hope that he would be permitted to enjoy His presence forever.

So will I sing praise unto thy name for evher - For the benefits which I have received, and hope to receive endlessly from thee, I will to all perpetuity praise thee.
That I may daily perform my vows - While I live, I shall יום יום yom, yom, "day by day," each day as it succeeds, render to thee my vows - act according to what I have often purposed, and as often promised. The Chaldee ends remarkably: "Thus I will praise thy name for ever, when I shall perform my vows in the day of the rederaption of Israel; and in the day in which the King Messiah shall be anointed, that he may reign."
The ancient Jews were full of the expectation of the Messiah; the Jews of the present day have given up their hope.

So will I sing praise unto thy name for ever,.... Or constantly; and not only in this world, but in that to come, for the favours before mentioned; for hearing his prayers; giving him a goodly heritage; prolonging the King's life; and preparing mercy and truth to preserve him;
that I may daily perform vows; which is done by praising the Lord, giving him the glory of all mercies, as vowed and promised; see Psalm 50:14. The Targum adds,
"in the day of the redemption of Israel, and in the day that the King Messiah shall be anointed, that he may reign.''

Thus for new blessings will new vows of praise ever be paid.