In the poem, the sounds of the sea waves breaking on the shore, serve as a symbol. Even though they are not explicitly described, the waves are implied by the phrase “eternal motion” (Line 7) that follows the mention of the sea in Line 5. The repeated crashing of the sea symbolizes the perpetual dynamic activity of God, which is just like the waves in their endless movement; the process never stops. As the speaker sees and hears the waves, he is already inclined to interpret the scene in spiritual terms, and now the sounds of the sea put him in mind God’s perpetual motion. He is awed by this thought and connects it to a “sound like thunder” (Line 8). In many passages in the Bible, the activity or voice of God is compared to thunder. In Psalm 29, for example, “the God of glory thunders, the LORD, upon many waters” (Verse 3, RSV).