This has become mine, That I observe Your precepts. Heth.
NASB95
This blessing has fallen to me, that I have kept your precepts.
ESV
This I had, because I kept thy precepts.
KJV

How is it, believer, that you are enabled to sing of the Lord's statutes—and to remember His name? This you have, because you keep His precepts. Thus you are able to tell the world, that in keeping His "commandments there is great reward"—that the "work of righteousness is peace; and the effect of righteousness, quietness, and assurance forever." Christian! let your testimony be clear and decided—that ten thousand worlds cannot bestow the happiness of one day's devotedness to the service of your Lord. For is it not in this path that you realize fullness of joy in "fellowship with the Father, and with His Son Jesus Christ?" "He that has My commandments, and keeps them, he it is that loves me; and he who loves Me shall be loved of My Father; and I will love him, and will manifest Myself to him—My Father will love him; and we will come unto him, and make our abode with him." If you were walking more closely with God in "the obedience of faith," the world would never dare to accuse religion as the source of melancholy and despondency. No man has any right to the hope of happiness in a world of tribulation, but he who seeks it in the favor of his God. Nor can any enjoy this favor, except as connected, in the exercise of faith, with conformity to the will, and delight in the law, of his God. Thus not only are the "statutes of the Lord right," but they "rejoice the heart." There is a sweetness and satisfaction in the work, as well as a good flowing out of it—a current as well as a consequent privilege—cheering the soul in the act of exercise, just as the senses are regaled at the very instant with the object of their gratification.

But let us remark how continually David was enriching his treasury of spiritual experience with some fresh view of the dealings of God with his soul: some answer to prayer, or some increase of consolation, which he records for his own encouragement, and for the use of the Church of God. Let us seek to imitate him in this respect; and we shall often be enabled to say as he does—This I had—this comfort I enjoyed—this support in trouble—this remarkable manifestation of His love—this confidence I was enabled to maintain—it was made my own, because I kept Your precepts.

This I had—not, this I hoped for. He speaks of "the promise of the life that now is"—that by which God clears away the charge, "It is vain to serve Him; and what profit is it, that we have kept His ordinances?" Nor is it any boasting of merit, but only an acknowledgment of the gracious dispensation of his God. Such a reward for such poor service, can only be undeserved "mercy," having respect, not to the worthiness of the work, but to the faithfulness of the promise. Perfect keeping, according to the legal requirements, there cannot be. Evangelical perfection, in aiming at the mark, and constantly pressing onward towards it, there may be.

How important therefore is it—in the absence of this Christian confidence—to examine, "Is there not a cause?" and what is the cause? Have not "strangers devoured my strength; and I knew it not?" Is the Lord "with me as in months past?"—with me in my closet?—with me in my family?—with me at my table?—with me in my daily employments and conversation with the world? When I hear the faithful people of God telling of His love, and saying—This I had; must I not, if unable to join their cheerful acknowledgment, trace it to my unfaithful walk, and say—This I had not, because I have failed in obedience to Your precepts; because I have been careless and self-indulgent; because I have slighted Your love; because I have "grieved Your Holy Spirit," and forgotten to ask for the "old paths, that I might walk therein, and find rest to my soul?" O let this scrutiny and recollection of our ways realize the constant need of the finished work of Jesus, as our ground of acceptance, and source of strength. This will bring healing, restoration, increasing devotedness, tenderness of conscience, circumspection of walk, and a determination not to rest, until we can make this grateful acknowledgment our own. At the same time, instead of boasting that our own arm, our own diligence, or holiness, "have gotten us" into this favor, we shall cast all our attainments at the feet of Jesus, and crown Him Lord of all forever.

He had this comfort, this remembrance of God, this power to sing, this courage to face the enemy, this hope in the promise, because he had earnestly observed the commands of God, and striven to walk in them. We are not rewarded for our works, but there is a reward in them. Many a comfort is obtainable only by careful living: we can surely say of such consolations, "This I had, because I kept your precepts." How can we defy ridicule if we are living inconsistently? How can we comfortably remember the name of the Lord if we live carelessly?

It may be that David means that he had been enabled to keep the law because he had attended to the separate precepts: he had taken the commands in detail, and so had reached to holiness of life. He who is not careful of the parts of the law cannot keep it as a whole. Or he may mean that by keeping certain of the precepts he had gained spiritual strength to keep others: for God gives more grace to those who have some measure of it, and those who improve their talents shall find themselves improving. Probably it is best to leave the passage open just as our version does; so that we may say of a thousand priceless blessings, "These came to us in the way of obedience." All our possessions are the gifts of grace, and yet it is unquestionably true that certain of them come in the shape of reward. Even when good things come to us in this way the reward is not of debt, but of grace. God first works in us good works, and then rewards us for them. This is a complex condescension, a chequer-work of goodness.

In this verse we have an apt conclusion to this section of the psalm, since it contains a strong argument for the prayer with which the section commenced. If we have been helped to remember our Lord's commands we may be sure that he will remember our necessities. The sweet singer had evidence of having kept God's precepts, and therefore he could the more properly beg the Lord to keep his promises. All through the passage we may find pleas, especially in the two remembers. "I have remembered your judgments," and "I have remembered your name"; "Remember your word unto your servant."

Exposition of Verses 57 to 64

YOU are my portion, O LORD; I have said that I would keep your words.

I entreated your favor with my whole heart: be merciful unto me according to your word.

I thought on my ways, and turned my feet unto your testimonies.

I made haste, and delayed not to keep your commandments.

The bands of the wicked have robbed me: but I have not forgotten your law.

At midnight I will rise to give thanks unto you because of your righteous judgments.

I am a companion of all them that fear you, and of them that keep your precepts.

The earth, O LORD, is full of your mercy: teach me your statutes.

In this section the Psalmist seems to take firm hold upon God himself; appropriating him (57), crying out for him (58), returning to him (59), solacing himself in him (61, 62), associating with his people (63), and sighing for his personal instruction (64). Note how the first verse of this octave is linked to the last of the former one, of which indeed it is an expansion. "This I had because I kept your precepts. You are my portion, O LORD; I have said that I would keep your words." Being many, these verses are still but one bread.