en_tn_lite_do_not_use/1th/03/05.md

I could no longer stand 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"