Psalms 4 and 5 make up a prayer rhythm. For the Hebrews a day consists of evening and morning as in Genesis 1. This is because rest is what we're made for and work is what we do. It's God's work that counts at the end of the day / life. He creates out of nothing. We arrange His raw materials.
Better still He is the God of my righteousness. (v2) He gives me my worth and justifies my place on earth. When I get this 'in peace I will lay me down to sleep.'
Other people are crazy busy chasing stuff as they love delusions and go after false gods. OK sometimes they do well and it makes them happy but theirs is nothing on the joy of the believer who can sleep in peace knowing It's You Lord alone who makes me dwell in safety. v9
In the middle, verses 5 & 6, is his bedtime routine when he hands over control of his life and activity. (Psalm 5 is his morning routine.) He speaks to the Lord, confident that the Lord is listening. He reflects on the day, bringing its frustrations to the surface without crossing the line into sin. No self pity or getting even permitted. He speaks and listens to his heart to understand himself. On his bed he offers up everything (work, family, finances, health, ambitions) to the Lord and rests his soul on Him just like he rests his head on the pillow.
As the song puts it
Lay your deadly doing down, down at Jesus' feet.
Stand in him, in him alone, gloriously complete.
Thanks for sharing Tim. This psalm reminds me that when we are in a right relationship with God, we get to experience His peace, in-spite of what our needs are - confident that our Father will undertaken for all our concerns.