Psalm 121:6 is not saying the moon has magical powers to hurt people. It is using poetic language to say that God protects people day and night , from visible dangers and hidden ones alike.

What the line means

In the verse, “the sun will not harm you by day, nor the moon by night,” the point is total protection, not a scientific claim about moonlight. The sun and moon stand for the risks people face during daytime and nighttime travel, especially in the world of ancient pilgrims.

Why the moon is mentioned

In the Bible’s poetic style, the moon can symbolize nighttime fears, sickness, or dangers people believed were connected with the night. Some readers also understand it more simply as part of a pair: sun by day, moon by night, meaning all times and all conditions.

Main message of the psalm

Psalm 121 is a reassurance that God “keeps” or watches over his people continuously. The bigger idea is that God protects your coming and going, your life, and your journey, not just your body in a narrow sense.

Plain-English paraphrase

A simple paraphrase would be: “God will protect you all the time, whether it’s bright outside or dark outside.” That is the heart of the verse.

TL;DR

It means the moon is not literally the danger; the verse is poetic shorthand for God’s complete protection, day and night.