John Calvin Commentary Psalms 119:168

"I have observed thy precepts and thy testimonies; For all my ways are before thee. TAV." — Psalms 119:168 (ASV)

I have kept your commandments and your testimonies. What the Psalmist had expressed more strongly, he now repeats more simply, adding a reason for it. He abbreviates the statement from the preceding verse only by omitting the word soul, which he used there, while joining testimonies to commandments. This is to show more distinctly that he does not speak exclusively of the rule for an upright and holy life, but also includes the whole covenant of salvation.

Indeed, the doctrine of the law could not be so sweet and attractive from its commanding what is right, if it did not at the same time display the free favor of God. The reason the Prophet assigns for keeping God’s commandments and testimonies—for all my ways are before you—is that the truth he well knew (namely, that nothing is hidden from God) served as a restraint to keep him devoted to cultivating godliness. For if we do not live as under the omniscient inspection of God, the fickle lustfulness of the flesh quickly carries us away, now one way and now another.

The meaning may also be this: that he made God the arbiter and judge of his life. For in scriptural language, those are said to walk before God, who refer all their actions to Him and, as it were, withdrawing themselves from human sight, present themselves at His judgment seat.

In this way, he indicates that he had endeavored not only to be free from all fault and blame before people, but also to offer to God a sound and sincere heart. Whichever of these meanings is adopted, he testifies that it is only when we consider that we have to deal with God—who searches the heart and from whose eyes nothing is hidden—that we will observe His law correctly.

This concluding clause may also be a form of solemn declaration, as if the Prophet had said, "Lord, you are the best witness of the faithfulness with which I have kept your law, for nothing is hidden from you." But he seems rather to have intended to suggest that the principle of his holy living was his having consecrated his life to God and having kept his thoughts fixed on the diverse presence.