He that laboureth laboureth for himself; for his mouth craveth it of him.
He that laboureth, laboureth for himself - literally, 'The soul of him that laboureth, laboureth,' etc.
For his mouth craveth it of him - literally, 'is bowed,' or 'boweth itself unto him,' as a suppliant craving food for its wants. Or, more literally, 'boweth itself upon him' - i:e., imposes labour upon him. Solomon exhorts here to 'labour,' which is man's appointed portion (Genesis 3:17-19; Ecclesiastes 6:7, "All the labour of man is for his mouth"). Labour tends to the good of him that laboureth, and supplies his pressing needs (cf. Proverbs 9:12). So in our spiritual needs labour (i:e., diligence and earnestness) is the path to the heavenly rest. The spiritual appetite created by God the Holy Spirit 'craves' laborious diligence of the man, so as to obtain the free gift of the bread of life.