Behold, I have a desire to thy precepts This is a repetition of what he declared a little before, with regard to his pious affection, and his love of righteousness; and that nothing was wanting but God to complete the work which he had commenced. If this interpretation be admitted, then, to be quickened in the righteousness of God, will be tantamount to being quickened in the way. The term righteousness is often put in this psalm for the law of God, or the rule of a righteous life. This view tends to make the two parts of the verse accord with one another. "Lord, this is now a remarkable kindness thou hast done me, in having inspired me with a holy desire to keep thy law; one thing is still necessary, that this same virtue pervade my whole life." But as the word righteousness is ambiguous, my readers may, if they choose, understand it thus: Restore, defend, and maintain me for the sake of thy goodness, which thou art wont to show to all thy people. I have already pointed out the exposition which I prefer.

Behold, I have longed after thy precepts - I have earnestly desired them. See the notes at Psalm 119:20.
Quicken me in thy righteousness - Make me to live; to live in obedience to thy righteous laws. See Psalm 119:25, note; Psalm 119:37, note.

Behold, I have longed - Thou searchest the heart; thou knowest that I have long desired thy salvation; thou seest that this desire still remains. Behold it! it is thy work; and through thy mercy I breathe after thy mercy.
Quicken me - I am dying; O give me the spirit of life in Christ Jesus!

Behold, I have longed after thy precepts: (f) quicken me in thy righteousness.
(f) Give me strength to continue in your word even to the end.

Behold, I have longed after thy precepts,.... After a greater degree of knowledge of them, and an opportunity of hearing them explained and enforced, and of yielding obedience to them; see Psalm 119:7;
quicken me in thy righteousness: in the way of righteousness, according to the word of righteousness, the Gospel, and with the righteousness of Christ revealed in it; and which is unto life, and quickens and comforts the heart, and from whence abundance of peace and joy flows.

Longed - After a more solid knowledge and constant performance of them. In - According to thy faithfulness.