expression, godan verb (-su)
do everything humanly possible; exhaust all means
A set phrase meaning to try every possible avenue within human power, often used when the outcome is uncertain and one must leave the rest to fate or a higher power.
人事を尽くして天命を待つ。
Do your best and leave the rest to fate.
彼は人事を尽くしたが、結果は
He did everything humanly possible, but the result didn't change.