This psalm is about how God speaks to us. Even though we’ve never seen God, we can know about him because of what he has created. The sun, mountains and the ocean are all things God created to show us how powerful and creative He is.
This psalm is a song the Isrealites would sing as they made a long journey to Jerusalem to worship God. The journey was never easy and could be very dangerous. But, the Isrealites trusted that God would get them safely to their destination.