Again, work brings money, which can then be exchanged for food and other necessities of life. Money is frozen work. Money is a man's proof that he has done work, and in particular, work that someone else has found of value. A dollar is evidence that the person holding it has done work that someone else considered worth paying for. Money is also traded for material goods, but if you think about it, those goods also represent work.
Food is grown, which takes work.
It's harvested, which takes work. It's carried to market, stored, arranged in bins, cooked, brought to the table, and eaten. The waste products are carried off, composted one way or another, and used to grow new food. The flow of material forms a circle of value, where each person in the chain has goods to pass on to another because he, in turn, has received goods from someone else. When we exchange money for a good or service, what we're really doing is exchanging work for work, or value for value.