What does Psalm 133:3 mean?
David offers a second simile to show the joy which comes when fellow believers live in harmony with each other.Mount Hermon is at the northeast boundary of ancient Israel. Its height and location made it a major source of water for the region. The Jews depended upon the early and latter rains and dew to water the otherwise dry land and enable crops to grow. The ultimate source of this lifegiving water was far from them, symbolizing the sovereign nature of God in providing for their needs. Dew symbolizes fruitfulness. Like the far-away source of a river's water, dew comes down from God; it is not something man produces.
Similarly, Christians cannot be fruitful by depending on their own intelligence, strength, and work. Zechariah 4:6 reports: "This is the word of the LORD to Zerubbabel: Not by might, nor by power, but by my Spirit, says the LORD of hosts." When believers live under the control of the Holy Spirit (Ephesians 5:18), good, pleasant, and refreshing results occur. They edify one another (Ephesians 5:19); they constantly offer thanks to God (Ephesians 5:20); they serve one another (Ephesians 5:21); love characterizes their family life (Ephesians 5:22–33; 6:1–4); and peace marks their workplace (Ephesians 6:5–9).