There was a Rishi named Dhaumya who had three disciples in his Gurukul - Upamanyu, Aaruni from Paanchaal country, and Ved. Once Guru Jee called Upamanyu and assigned him some cows to take care of. He started taking them to graze in the morning and bring them back in the evening. After a while, Muni asked - "How do you support yourself? You look quite healthy." Upamanyu said politely - "Guru Jee, After I hand over my Bhikshaa (alms) to you, I go again to ask for alms and I eat that." Guru Jee said - "This is bad, because it is not a rule for a Brahmchaaree that he should go for alms twice. Youa should not do this." "Yes Guru Jee." Saying this Upamanyu came back.

After a while Guru Jee again found him healthy, so he called him and asked again - "Child Upamanyu, You don't get food from the Aashram, you don't get food from second alms, then how do you support yourself, you look quite healthy." Upamanyu said - "I live upon the milk of these cows." Guru Jee said - "Son, It is not appropriate to drink milk of these cows without my permission." "Yes Guru Jee." and he went away to tend the cows.

After a while, Guru Jee again found him healthy, so he again called him and when he came and stood before he asked him - "Upamanyu, You don't get food from Aashram, you don't go to the alms for a second time, nor you are drinking milk of these cows, still you are healthy. How do you support yourself now?" Upamanyu said - "I sip the froth these calves throw out of their mouth while sucking their mother's teats." Guru Jee said - "These calves must be throwing much froth for you out of generosity. Don't you think that by doing this you should be sharing their full meal? It is unlawful for you to drink the froth like this." And Upamanyu accepting his mistake again went away to tend the cows.

Upamanyu Falls in a Well
Now he didn't have anything to eat - no alms, no milk, no froth. Once, out of hunger, Upamanyu ate Aak leaves (by eating these leaves one becomes blind) and became blind. As he was walking around, he fell into a pit, thus could not return home that evening. When Guru Jee found the cows returning home alone and did not see Upamanyu in the evening, he got worried about him. He had restrained him from eating everything, so he didn't know how he would be. Thinking thus, he himself went in search of him. He called out in the forest - "O Upamanyu, Where are you?" Upamanyu replied - "I am here in this well. I ate Aak leaves, so I became blind and fell in this well." Guru Jee got very sad he said - "Pray Ashwinee Kumaar, they will restore your sight."

And Upamanyu prayed them. Ashwinee Kumaar appeared before him and gave him a cake to eat. Upamanyu said - "You have said correctly, but I cannot take this cake without first offering to my Guru." Ashwinee Kumaar said to him - "Once before your Guru invoked us and we gave a cake to him too, but he had eaten it without offering to his Guru. You also do the same what your Guru did." Upamanyu said - "I beg your pardon, but I cannot take this cake without offering to him first." Ashwinee Kumaar got very pleased with him and said to him - "We are very pleased with you. Your Guru's teeth are of black iron, but your teeth will be of gold. Your eyes will be all right and you will have good fortune." He got his sight back, came out of the well, and greeted Guru Jee. Guru Jee also blessed him with the knowledge of Ved and all Dharm Shaastra.