Eat, drink, and be merry, for tomorrow we die a conflation of two biblical sayings, Ecclesiastes 8:15, ‘Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be merry’, and Isaiah 22:13, ‘Let us eat and drink; for to morrow we shall die.’ There are a number of humorous variants.
eat humble pie make a humble apology and accept humiliation. Humble pie is from a pun based on umbles ‘offal’, considered as inferior food.
eat one's terms in the course of studying for the Bar, be required to dine a certain number of times in the Hall of one of the Inns of Court.
eat to live, not live to eat proverbial saying, late 14th century, distinguishing between necessity and indulgence; Diogenes Laertius says of Socrates, ‘he said that other men live to eat, but he eats to live.’ A similar idea is found in the Latin of Cicero, ‘one must eat to live, not live to eat.’
have someone eating out of one's hand have someone completely under one's control.
he that would eat the fruit must climb the tree someone who wishes to attain success must first make the necessary effort. The saying is recorded from the early 18th century, but a similar idea is found in the late 16th century, in J. Grange's Golden Aphroditis (1577), ‘Who will the fruit that harvest yields, must take the pain.’ (Compare no pain, no gain.)
we must eat a peck of dirt before we die often used as a consolatory remark in literal contexts; saying recorded from the mid 18th century. A peck is a dry measure, the equivalent of two gallons.
you are what you eat proverbial saying, mid 20th century, sometimes attributed to the French gastronome Anthelme Brillat-Savarin, who wrote in his Physiologie du Goüt (1825), ‘Dis-moi ce que tu manges, je te dirai ce que tu es [Tell me what you eat, and I will tell you what you are].’ An equivalent proverb in German is Mann ist was Mann isst ‘man is what man eats.’
See also big fish eat little fish, the cat would eat fish, eat crow, eat a person's salt, if you don't work you shan't eat.