“Thou wilt keep him in perfect peace whose mind is stayed on Thee,
because he trusted in Thee.”
~ Isaiah 26:3 KJV
That verse hangs on the wall directly across from my bed. The picture (not shown due to copyright) is an original illumination, given to us as a wedding gift over 40 years ago. At the most difficult of times, I would look and say that verse over and over until it sunk into my heart.
The amplified classic version gives more insight into what that means: Isaiah 26:3, saying of God:
You will guard him and keep him in perfect and constant peace whose mind
[both its inclination and its character] is stayed on You,
because he commits himself to You, leans on You,
and hopes confidently in You.