Albert Barnes Commentary Psalms 119:130

"The opening of thy words giveth light; It giveth understanding unto the simple." — Psalms 119:130 (ASV)

The entrance of thy words giveth light—The Septuagint translates this as “the manifestation (or declaration)—ἡ δήλωσις hē dēlōsis—of your words enlightens.” The Vulgate translates it similarly. Luther renders it, “When your word is revealed, it delivers us and makes the simple wise.” DeWette translates it as, “The opening (revelation) of your word,” etc.

The Hebrew word—פתח pethach—means an “opening” or “entrance,” such as that of a gate (Joshua 20:4; Judges 9:35). It can also mean “a door,” like that of a tent or the temple (Genesis 18:1; 1 Kings 6:8), or the gate of a city (Isaiah 3:26). Furthermore, it signifies opening, insight, or instruction.

The word, as used here, seems to denote the opening or unfolding of the word of God—the revelation of that word to the mind.

A door is open so that we may enter a house; a gate is open so that we may enter a city. In this way, the meaning of the word of God is “opened” to us, so that we may, as it were, enter and see its beauty.

The language, therefore, does not denote the entrance of that word into the mind, but rather its being made open to us, so that we may perceive its beauty or may ourselves “enter” into its meaning, its mysteries, and its beauties.

It giveth understanding unto the simple—The word rendered “simple” literally means “those who are open to persuasion,” or who are easily enticed or seduced. It then refers to the credulous (Proverbs 14:15) and then to the “inexperienced.” (See Psalm 19:7, note; Psalms 116:6, note).