Sage Nandisen was a great ascetic and well-versed in the scriptures. He took a vow to serve monks with utmost devotion. His devotion of serving the monks was even popular in the heavens. One day, his services were openly applauded by Indra in an assembly of angels. One of the angel could not believe this and decided to test sage Nandisen. 

The angel gods can assume any form they desire in a moment and can reach anywhere in the wink of an eye. This god arrived at the outskirts of the village where the sage Nandisen was to test his "Vow of Servitude" and assumed the forms of two monks. One became a very old and diseased monk, while the other became a young and healthy monk.

It was the day on which the sage Nandisen was to break his fast. After he came from collecting gochari (alms) and was about to break the fast, the young monk came to him and said, "Oh blessed one! There is a very old monk suffering from diarrhea, extreme thirst, and hunger. He is weak and needs your help." Hearing these words, sage immediately got up and took pure water with him and went to the place where the old monk was. Seeing Nandisen, the old monk at once raged, "Oh you wretch, I am lying here suffering, and you did not even care to find if anyone needs help."

Sage Nandisen was not offended by these words. He had developed virtues of tolerance, forgiveness, and compassion. He calmly replied, "Oh the best of the monks, kindly excuse my oversight. I have brought pure water for you to drink."

He helped the old monk drink the water. He cleaned his clothes, his body, and helped him sit up. The old monk once again became irritated. He frowned saying, "Oh you fool, and don’t you see that I am too weak to sit. What are you doing to me?"

Sage Nandisen said, "I will support you." Having seated the old monk he said, "Oh reverend monk, if you desire I shall carry you to upashray (place where monks stay temporarily) where you will be more comfortable. The monk replied, "Why are you asking me? You may do so as you wish."

Sage Nandisen make the monk sit on his shoulders, and slowly proceeded further. He walked slowly, watching every step carefully. The old monk (angel god) was determined to test him, so he increased his own weight gradually. With the increase in weight on his shoulder, sage Nandisen began to tremble, and he almost fell. The monk said, "Oh you wretch, what is wrong with you? Don't you know how to walk? You are shaking my entire body. Is this any way to serve the sick?" His words were very bitter and harsh, but sage Nandisen was not disturbed at all. He said, "Pardon me. I shall be more careful."

Later, the old monk passed stool and the odor was unbearable, but the sage was not disturbed at all. He ignored this and continued walking and took care not to offend the monk with any of his faults. On the way, he thought about how to cure the monk.

He arrived with the monk at the upashraya. During all this time the old monk was watching sage Nandisen and did not see any change in helping nature of sage Nandisen even after all of the aggravation. So the old monk turned back into an angel and paid homage at once to the sage Nandisen saying, "Blessed are you. Oh sage, you are the illustration of a real monk. You are as described by Lord Indra. I am very pleased with you and grant you whatever you choose."

"Oh god, this human life is very rarely achieved. Nothing is more valuable than human existence. I am content. I crave for nothing." The god bowed his head at the feet of the sage. The god returned to his abode, applauding the merits of the sage.