A great Teacher was walking down the road with two students. They had not eaten for three days when an old woman offered them some cold stew. She had no wood to make a fire and heat it, and the Teacher gently refused the kind offer. The two students did not and ate greedily.

They continued on their journey and afer a li or two one of the students said, "I feel that I will be ill" and vomited the stew into his bowl. Immediately the other did the same.

The Teacher took the bowls, pulled out his spoon, and ate the contents of both bowls. "I knew," he said, "that if I were patient I should have a warm meal."

That koan contains the answer to your question, if only you can understand it.