The Gandharva king had addressed Arjuna as a descendant of Tapati. Aruna wanted to know more. The gandharva then told the story of Tapati.
The sun god is the one the provides light to all. Tapati was his daughter, younger to Savitri. There was no one who was equal to her in beauty. She was always engaged in meditation and tapasya, so she was known as Tapati in the triple world. seeing her , the sun thought that there was none in the three worlds who deserved to be her husband. This led him to sleepless nights.
On the earth, Samvarana, a kuru king was a great devotee of the sun. Seeing his devotion, the Sun God thought this was the ideal husband for his daughter.
One day Samvarana,the handsome and powerful king went hunting. On the way, exerted, his horse fell down and died. The king continued on foot till he came across a beautiful maiden. He was spellbound by her beauty. The sight of that maiden maddened the king. The king's heart and eyes were captivated by the damsel. The king wanted to know who she was. Without answering the king, the maiden just vanished. The king collapsed in grief.
The maiden reappeared and asked the king to rise. The maiden helped him to his feet. The king in turn kept praising her beauty and wanted to know all about her. She said she was Tapati, the daughter of the Sun, and if the king wished, he could could ask her hand in marriage, from her father.
Saying this, went back to the skies. Looking for the king, his courtiers found him lamenting in the forest. Thinking the king had collapsed with hunger, his ministers tried to offer him food, but the king had lost his senses. The king then began worshiping the Sun God and then thought of his chief priest, Vasishtha. Vasishtha knoew what had happened. He assured the king, that he would do all he could to unite the king with Tapati. Vasishtha then met the Sun God and asked for his daughter's hand in marriage for the king. The Sun God agreed and let Tapati go with Vashishtha to the king. Thus the king got married to Tapati.
Arjuna then wanted to know more and the Gandahrva continued.
Vashishtha was the son of Brahma and the husband of Arundhati. He had great control over emotions. And it was obtaining a priest like Vashistha, the king was able to get Tapati as his wife. The Gandharva then said, it was always beneficial to have a priest with them, whereever they went. Arjuna still wanted to know about Vashistha.
When Samvarana got married to Tapati, he proclaimed Vashistha, a ruling king, when he roamed around with his new wife. For twelve years there was no rain. On seeing this, Vashistha sent for the king. The moment the king back, it started raining and all was well.
It was this Samvarna in whose dynasty the Pandavas were born, thus they were called descendants of Tapati.
Arjuna then wanted to know about Vashistha and Vishwamitra. The gandharva continued.
Vishwamitra was a king. One day, while out hunting, he lost his way and reached the ashrama of Vashishtha. The sage welcomed the king and fed him fruits and offered clarified butter. Vashistha had a cow that could give all that was desired of her. She could yeild fruits, grains, juices and any other items that she was requested to give. She could also give robes and gems, if asked for.
The king coming to know of this cow, wanted it for himself. He was willing to exchange land in place of the cow.
When Vashishtha refused, Vishwamitra tried to take the cow by force. The cow called out for help. Vashistha then said , the cow needed to help itself. The cow then took an a terrible shape and attacked Viswamitra's troops . From her tail she began to rain showers of burning coals all around. Then she brougt forth an army that destroyed the king's army. Vishwamitra feld. He then thought, true power was in being a sage, being a king was worthless. He then gave up his kingdom and became a rishi.
There was once a king called Kalmashapada of the Ikshvaku race. Vishwamitra wanted to make this king his disciple.The king not knowing this, approached Saktri who was coming from the opposite way. This was a son of Vashistha. The king asked the rishi to step aside so he could pass. The rishi saying, kings needed to bow down before rishis and give them right of way. The king struck the rishi, who cursed him saying he would be born as a Rakshasha. Vishwamitra saw this happening. His defeat in hands of Vashistha was not forgotten.
The sage had a rakshasha enter the body of the king. Once a rishi came to the king for food. The king told the rishi to wait. Then when he remembered, he asked his cook to send some food to the rishi, but he was not found. Angered, he told his cook to feed the rishi, human flesh.
Angry, the rishis in the kingdom cursed the king to become a flesh eating rakshasha. The king then sought out Saktri, and said as he had been cursed to eat human flesh, he would start by eating this son of Vashistha. After he had eaten him, Vishwamitra told him to go and eat up all the sons of Vashishtha. Learning that all his sons had been killed because of Vishwamitra, Vashistha remained calm.
He left his ashrama and began roaming around. He tried to kill himself but he found it was not possible. Coming back, he heard someone reciting the vedas. He then found this was the unborn son of Saktri, speaking from his mother's womb.
One day he saw Kalmashapada possessed by the rakshasha. Sprinkling holy water, he released the king from the curse.
The king bowed down before the sage and begged for forgiveness. The king being childless asked the sage how he could get a son. The king entered his kingdom, called Ayodhya along with Vashishtha. He then had a son whom he named Asmaka.
In Vashishtha's ashram, his daughter in law gave birth to a son called Parasara.