What does Psalm 46:3 mean?
Continuing a theme of assurance, this verse comes from the people of Israel who celebrate God as their shelter and support. The prior verse referred to two of nature's most surprising and damaging disasters: earthquakes and landslides. Even in the face of those, however, God's people can trust in His goodness (Psalm 46:1–2).Here, the psalm evokes the chaotic nature of the sea. Not even the roaring, foaming, and swelling of the ocean can cause God's people to fear. The otherwise-immovable mountains may tremble when the sea erupts, but God's people need not shake in fear. In practice, of course, fear in the face of danger is a normal human reaction (Matthew 8:23–25). Reminders such as this are indications of how we can, or should, respond, not necessarily how we always will react.
This imagery of chaos may apply to international disturbances. In His Olivet Discourse, Jesus predicted that in the end times "nation will rise against nation, and kingdom against kingdom" (Matthew 24:7). Although horrific international confrontation will take place in the tribulation period, believers today are bombarded with news about international strife, military threats from rogue nations, and the buildup of nuclear arms. Nevertheless, we need not tremble. Our God knows all about the nations' unrest and threats (Ecclesiastes 12:14). He offers peace of heart and mind to those who trust Him. Someday our heavenly Father will hold the rebellious nations in derision and will speak to them in His wrath (Psalm 2:4–5).
The term se'lāh is not fully understood, but it seems to be either a musical reference or something like the exclamation "amen!"