Psalm 3

O Lord, I have so many enemies; so many are against me.
So many are saying, "God will never rescue him!"
But you, O Lord, are a shield around me, my glory, & the one who lifts my head high.
I cried out to the Lord, & he answered me from his holy mountain.
I lay down & slept. I woke up in safety, for the Lord was watching over me.
I am not afraid of ten thousand enemies who surround me on every side.
Arise, O Lord! Rescue me, my God!
Slap all my enemies in the face! Shatter the teeth of the wicked!
Victory comes from you, O Lord. May your blessings rest on your people.
Psalm 3 NLT

Footnotes from the NLT Life Application Study Bible:
3:1,2 David felt like he was in the minority. There may have been as many as 10,000 soliders surrounding him at this time. Not only did David's enemies view life differently, they actively sought to harm him. As king, David could have trusted his army to defeat Absalom. Instead, he depended upon God's mercy; therefore, he was at peace with whatever outcome occured, knowing that God's great purposes would prevail. We can overcome fear by trusting God for his protection in our darkest hour.

3:5 Sleep does not come easily during a crisis. David could have had sleepless nights when his son Absalom rebelled & gathered an army to kill him. But he slept peacefully, even during the rebellion. What made the difference? David cried out to the Lord, & the Lord heard him. The assurance of answered prayer brings peace. It is easier to sleep well when we have full assurance that God is in control of circumstances. If you are lying awake at night worrying about circumstances you can't change, pour out your heart to God, & thank him that he is in control. Then sleep will come.