Gandaki was a Veshya (prostitute) in the country of Magadha, she was the most beautiful of all the Veshyas. She earned plenty of wealth.
One day she went to the Satsanga of a monk, Swami Brahmanandaji.
Swami Brahmanandji used to discourse on spiritual topics every evening in the local Vishnu temple. On the day Gandaki went to the Satsanga, the Swamiji was discoursing on the subject of Shree Dharma with special reference to Pativrata Dharma. Gandaki was much impressed by the lecture of the Mahatma. She repented and wept bitterly. On her return home she could not get a wink of sleep at night. She thought "I am a wicked women. I am living by selling my chastity. I will fall into the greatest of hells. Who can save me now? I have wasted my life. I am no better than a beast. Who can be more foolish than me to waste away the precious life in this wretched manner?"
The next day Gandaki approached the Swamiji wet with Bhakti and full of Bhava. She said, "O Swamiji! Thou art my sole refuge. I am the worst of all sinners I have been impressed by your talk last evening. I have a new inner life now. Kindly lead me on to a nobler life. There is no end to the sins committed by me. Is there any hope for my redemption? Can I also become a Pativrata by following my position in life? Please enlighten me. I shall do as commanded by you. I shall strictly follow all your instructions."
Swami Brahmanandji said, "O Gandaki, do not get worried. Do not weep. There is hope for you also. Even a Veshya like you can become a true Pativrata. Follow my instructions carefully. Accept the first man who calls at your door in a particular day as your husband. Serve him with great devotion and faith. Think that the Lord Himself has come in his form to bless you. Worship him and serve him whole-heartedly. See Lord Vishnu in the human form of your Pati. Do not care for his beauty or the high offer of wealth. Even if another suitor offers lacs and crores you should not accept it. Serve the very first man who comes to you door."
Gandaki took the instructions to heart and went home after duly prostrating herself before the revered Swamiji. She put into practice all the instructions of the Swamiji strictly and followed the Pativrata Dharma.
Once a discussion took place in Vaikunta Loka as to who was the most devoted of all women and who strictly followed the Pativrata Dharma. Many names were mentioned but no definite conclusion was arrived at in the conference. In the meanwhile Rishi Narada and Durvasa stepped in. The Rishis were duly honoured by the assembly. Narada accepted the kind hospitality and enquired of Lord Vishnu as to the point of issue. After due explanation Rishi Narada said, "None can equal Gandaki in Pativrata Dharma. Gandaki is a Veshya of Magadha. Now she excels all others in the practice of Pativrata Dharma." The whole assembly of Devas was astounded at this very strange revelation of Narada. They all decided to test Gandaki. Narada explained fully her principles and Lord Vishnu agreed to go and test her.
Lord Vishnu assumed the form of a leper and called at Gandaki's house. She responded to the call and came out, only to see an ugly looking leper with bleeding wounds all over his body. She enquired the purpose of his visit to her house. The leper said, "Today I wish to live with you. I have heard much of your devotion to Pati and with that you take me as your Pati (husband) for today."
Gandaki accepted the offer most willingly. She said, "O Lord! Thou hast graced my house today and blessed me. Really you are my Patidevata. I shall serve thee nicely." She led the leper into her inner apartments, washed his wounds and dressed them after giving a bath to the whole body. She dressed him in rich costumes. She prepared a most delicious meal and fed him sumptuously. She danced and sang highly devotional songs. Her husband was greatly pleased. She took the leper to a well decorated bedroom adorned with the best of flowers, curtains and pictures. There were fragrant flowers, agarbattis and perfume, and the whole room was illumined on all sides by lamps fed with ghee. She anointed him with scents and adorned him with garlands. She then made him sleep on a silken bed.
Due to overeating, the leper began to suffer from severe purging and the whole bed was defiled by his motions. Gandaki removed all his clothes, washed them, dressed him afresh and made him sit on a clean cushion. Again the Patidevata started purging. Once again Gandaki washed the clothes, removed all the faecal matter and made him sit on a clean place. In this way she spent the whole night in changing the clothing and cleaning the excretions, she did all the seva with absolute calmness, without the least displeasure, ignorance or Ghrina. She exhibited wonderful patience strength of devotion to the Pati.
Early the next morning the poor husband breathed his last, being unable to stand the effect of the night's purging. Gandaki wept bitterly. The news spread everywhere. The dead body emitted a foul odour, so much so that no one dare go near it. It was so fierce to look at, like a ghost or devi, Gandaki herself attended to the funeral rites of her husband. She prepared the funeral pyre in front of her house and placed the corpse on the pyre. True to the vow of Pativrata Dharma she decided to consign her body to the flames together with that of her husband. She meditated on the form of the Lord in the form of the husband lying on the pyre. She then lit fire to the dead and entered into the bursting flames. She did not want to love anyone after the death of her husband. Glory, glory to Gandaki!
Lo! At once Lord Vishnu appeared before her. There was neither the dead body nor the funeral pyre. Gandaki prostrated herself before the Lord in all love and sincerity. The Lord blessed her and said, "You are the best of my devotees. Today I have seen your glory of Pativrata Dharma. May you live long! May you choose a boon from me."
Gandaki said, "O Lord! I crave for nothing, the goal to be attained. What shall I do with boons, I want nothing." The Lord was still more impressed with her one-pointed devotion and dispassion. He said, "I am anxious to grant you a boon. You must accept something from me. Tell me what you desire. Do not delay any longer." Gandaki replied, "Blessed Lord! I am thrice blessed. May You be pleased to ever live in my lap and make me happy for ever. I want no other boon". The Lord said, "Be it so. You shall be a river in Nepal and shall be known by the name 'Gandaki', I shall ever dwell in your lap in the form of Saligrama." Saying this the Lord at once disappeared.
Even today the Saligrama of Lord Vishnu are seen on the banks of the river Gandaki in Nepal. Thus is the origin of the river Gandaki, Glory to Pativrata Dharma! Glory to Pativratas! May India abound in Pativratas and highly exalted souls! May they be ideals of womanhood for modern India, nay the whole world!