This passage deals with the perfect righteousness of Jehovah and his word, and expresses the struggles of a holy soul in reference to that righteousness. The initial letter with which every verse commences in the Hebrew is “P”, and the keyword to us is PURITY.
Psalm 119 Verse 137. Righteous art thou, O LORD. The Psalmist has not often used the name of Jehovah in this vast composition. The whole psalm shows him to have been a deeply religious man, thoroughly familiar with the things of God; and such persons never use the holy name of God carelessly, nor do they even use it at all frequently in comparison with the thoughtless and the ungodly. Familiarity begets reverence in this case. Here he uses the sacred name in worship. He praises God by ascribing to him perfect righteousness. God is always right, and he is always actively light, that is, righteous. This quality is bound up in our very idea of God. We cannot imagine an unrighteous God.