“O LORD, how many are my foes! Many are rising against me” (1). David’s enemy is from his own household, his son Absalom (v1). He is overwhelmed by danger and sorrow, but in the middle of all this David can sleep well (v 5) because he has God as a shield and his glory. When we encounter difficult times, even those from within our own families, we can place our trust in the one who fights our battles.
Salvation is what God does (v 8). He will “lift our head” and keep us safe, so we can sleep in peace.