2 Corinthians 8 - 10
St. Paul speaks about his weakness and his thorn or weakness he can not remove
“Three times I pleaded with the Lord to take it away from me. But he said to me, “My grace is sufficient for you, for my power is made perfect in weakness.”Therefore I will boast all the more gladly about my weaknesses so that Christ’s power may rest on me. That is why, for Christ’s sake, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong.”
Isaiah 30: 15
15 This is what the Sovereign Lord, the Holy One of Israel, says:
“In repentance and rest is your salvation,
in quietness and trust is your strength,”