Albert Barnes Commentary Psalms 119:112

"I have inclined my heart to perform thy statutes For ever, even unto the end. SAMEKH." — Psalms 119:112 (ASV)

I have inclined mine heart - The Hebrew word properly means “to stretch out” or “to extend”—as the hand (Exodus 8:6, Exodus 8:17). Then it means to incline, to bow, or to depress.

Here the idea is that he had “given” that “direction” to the inclinations of his heart; he had resolved or purposed. He refers to an act of choice on his part, meaning that he had preferred this course or made this a solemn intention.

Though every right inclination of the human heart is to be traced to divine agency, it is also true that a person is active in religion. One's own mind resolves, chooses, and prefers. True religion is, therefore, the actual choice or preference of all who serve God rightly. See the notes at Psalm 119:59.

To perform thy statutes alway - Margin, as in Hebrew, “to do.” He meant to do the will of God. He intended to do this constantly, even forever. No one can be a truly pious person who has any disposition or any purpose “ever” to turn away from the service of God.

Even unto the end - See Psalm 119:33. It means to the end of life, to the end of all things.