King James Version (KJV)
He that laboureth laboureth for himself; for his mouth craveth it of him.
Modern English
A worker's appetite works for him; his mouth urges him on.
Hebrew
נֶ֣פֶשׁ עָ֭מֵל עָמְלָ֣ה לּ֑וֹ כִּ֣י אָכַ֣ף עָלָ֣יו פִּֽיהוּ׃
nepesh ʿamel ʿamlah lvo kiy ʾakaf ʿalayv piyhv