נֶ֣פֶשׁ עָ֭מֵל עָ֣מְלָה לּ֑וֹ כִּֽי־אָכַ֖ף עָלָ֣יו פִּֽיהוּ׃
C’est pour lui-même que travaille le laborieux, car pressantes sont les exigences de sa bouche.
Rashi
when his mouth forces him When his mouth forces him and demands food, then his labor stands up for him, for he eats what he has already worked for.