What does Psalm 19:9 mean?

The "fear of the LORD" seems like a strange term for the law God gave to Israel, but the Law was intended to teach the people of Israel to fear the Lord. The meaning of "fear," here, is the archaic sense of profound respect, humility, and acceptance. This is not a sense of panic, but of deference. This statement points out that reverential fear of the Lord is clean and endures forever. Unlike false religions that are defiled, God's Word is undefiled and everlasting. A judge may render an inaccurate decision, but God's judgments are true, David writes, and they are thoroughly righteous.

One of the instructions the Lord gave to Israel's king appears in Deuteronomy 17:18–19. It directs him to "write for himself in a book a copy of this law, approved by the Levitical priests. And it shall be with him, and he shall read in it in all the days of his life, that he may learn to fear the LORD his God by keeping all the words of this law and these statutes, and doing them." In Psalm 34:11 David wrote, "Come, O children, listen to me; I will teach you the fear of the LORD."