# I could no longer endure it

Paul is describing his own emotions by using an idiom. Alternate translation: "I could not continue to wait patiently" (See: [[rc://en/ta/man/translate/figs-idiom]])

# I sent

It is implied that Paul sent Timothy. This can be made explicit. Alternate translation: "I sent Timothy" (See: [[rc://en/ta/man/translate/figs-explicit]])

# our labor

"our hard work among you" or "our teaching among you"

# in vain

"useless"