Paul speaks of their ceasing to help him as if they had physically turned away from him. They abandoned Paul because the authorities had thrown him into prison. AT: "have stopped helping me" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "chain" is a metonym for being in prison. Onesiphorus was not ashamed that Paul was in prison but came to visit him frequently. AT: "was not ashamed that I was in prison" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# May the Lord grant to him to find mercy from him
"May Onesiphorus receive mercy from the Lord" or "May the Lord show him mercy"
# to find mercy from him
Paul speaks of mercy as if it were an object that could be found. (See: [[rc://en/ta/man/translate/figs-metaphor]])