Psalms 119:1

The psalmist here shows that godly people are happy people; they are, and shall be, blessed indeed. Felicity is the thing we all pretend to aim at and pursue. He does not say here wherein it consists; it is enough for us to know what we must do and be that we may attain to it, and that we are here told. All men would be happy, but few take the right way; God has here laid before us the right way, which we may be sure will end in happiness, though it be strait and narrow. Blessednesses are to the righteous; all manner of blessedness. Now observe the characters of the happy people. Those are happy, 1. Who make the will of God the rule of all their actions, and govern themselves, in their whole conversation, by that rule: They walk in the law of the Lord, Psa 119:1. God's word is a law to them, not only in this or that instance, but in the whole course of their conversation; they walk within the hedges of that law, which they dare not break through by doing any thing it forbids; and they walk in the paths of that law, which they will not trifle in, but press forward in them towards the mark, taking every step by rule and never walking at all adventures. This is walking in God's ways (Psa 119:3), the ways which he has marked out to us and has appointed us to walk in.

— Matthew Henry's Concise Commentary (public domain)