This story is based on Chandogya Upanishad
There were two Rishi – Rishi Shaunak and Abhiprataari. They were the worshippers of Vaayu Dev, the wind god. One day a hungry young Brahmchari came begging for food at lunch time to these Rishi.
When the Rishi refused to share with him the food that they were about to take especially in an Ashram, he decided to question them.
“Which God do you worship?” was his first question.
One of the Rishi answered – “My deity is Vaayu Dev who is also called Prana”.
The young boy said – “The world takes shape in Prana and merges also in it at the end. Prana pervades all that is visible and invisible. Then for whom have you cooked this food?
If Prana pervades the Universe, he also pervades in me and is the cause of my hungry body. So by denying food to me you are denying the food to your deity.”
The Rishi felt ashamed and invited the young man to share their food.