|Vasistha & Arundhati performing Yagna
The tale of Vashistha
Sage Vashistha was Ram's guru and the Rajpurohit of Ikshwaku dynasty. He was a peace-loving, selfless, intelligent and great Rishi. He had established Gurukula (residential college) on the banks of the river beas, where he and his wife Arundhati were taking care of thousands of students.
Vashistha was the Sadguru of his time, possessing 20 "kala's" (divine arts) and had complete knowledge of the whole cosmos and the god. Many of his Shlokas are found in Vedas as well.
Vashistha summons Kamadhenu alias Sabala, the cow of abundance, to provide for a feast
Vashista possessed a cow named Nandini daughter of Kamadhenu who could instantly produce food enough for a whole army. The king Kaushika (later called Vishwamitra), who visited Vashistha's hermitage, was very impressed with the cow and tried to take it away from Vashistha by force, but Kamadhenu/Nandini's spiritual power was too great for him.
After being unable to conquer Nandini, Vishwamitra decided to acquire power himself through penance like Vashistha. He gained much power and many divine weapons from Shiva. Once again he attempted to conquer Kamadhenu/Nandini. But even the divine weapons he acquired could not defeat the power of Kamadhenu/Nandini.
Vishwamitra finally decided to become a Brahmarishi himself, he renounced all his possessions and luxury and led the life of a simple forest ascetic.
The tale of King Dileepa
King Dileepa or Dilip was a king of the Raghuvamsha dynasty. He had a wife named Sudakshina, but they had no children. For this reason, Dileepa visited the sage Vashistha in his ashram, and asked him for his advice. Vashistha replied that they should serve the cow Nandini, child of Kamadhenu, and perhaps if Nandini was happy with their service, she would bless them with a child. So, according to Vashistha, Dileepa served Nandini every day, and attended to her every need for twenty-one days. On the twenty-first day, a lion attacks Nandini. Dileepa immediately draws his bow and tries to shoot the lion. But he finds that his arm is paralysed and cannot move. He reasons that the lion must have some sort of divine power. As if to confirm this, the lion started to speak to him. It said that Dileepa had no chance of saving the cow because the cow was the lion's chosen meal. The lion tells Dileepa to return to Vashistha's ashram. Dileepa replies by asking if the lion would let Nandini go if he offered himself in Nandini's place. The lion agreed and Dileepa sacrificed his life for the cow. But then the lion mysteriously disappeared. Nandini explained that the lion was just an illusion to test Dileepa. Because Dileepa was truly selfless, Nandini granted him a son.
Arundhati and Vashishtha pair of stars
In traditional Indian astronomy, pair of Alcor and Mizar in constellation Ursa Major is known as Vashishtha and Arundhati
Mizar is known as Vasistha and Alcor is known as Arundhati in traditional Indian astronomy. The pair is considered to symbolize marriage (Vashishtha and Arundhati were a married couple) and, in some Hindu communities, priests conducting a wedding ceremony allude to or point out the constellation as a symbol of the closeness marriage brings to a couple.
Brahmrishi Vashistha had an Ashram in Ayodhya that was spread over 40 acres (160,000 m2) of land. Today all that remains of it is a small ashram in about one fourth of an acre of land. The ashram has within it a well that is believed to be the source of the river Saryu. Brahmarishi Vashistha was the Guru of the Suryavamsha. The King at that time was King Ishvaku who was the king of Ayodhya. He was a noble king and thought of the well being of his subjects. He approached Sage Vashista telling him that the land had no water and requested him to do something to let the kingdom have adequate water. Sage Vashistha performed a special prayer and the river Saryu is said to have started flowing from this well. Sarayu is also known as Ishvaki and Vashisti. It is said that the well is connected underground with the river. Many spiritual people who visit this ashram find an enormous spiritual energy around this well. Some believe that this is one of the better spiritual tirth's in Bharat (India).
There is also another ashram past Rishikesh on the way to Kaudiyala on the Devprayag route that is known as Vashistha Guha Ashram. The ashram itself is located on the banks of the River Ganges and it is a very beautiful place. It has a wonderful long cave with a large dark Shivaling installed at the end inside. The head of the ashram is a Sanyasi monk of South Indian origin by the name of Swami Chaitanyanandji. There is also another cave smaller to the side facing the river called 'Arundhati's Cave', also known as 'the Jesus Cave', since the 1930's when Papa Ramdasji had mentioned in his book about his vision of Lord Jesus there.
Source : http://en.wikipedia.org/wiki/Vashistha