Agasthiyar (Sanskrit:अगस्त्य, Tamil:அகத்தியர் Akattiyar, Malay: Anggasta, Thai: Akkhot) was a V edic Siddhar or sage. Agasthiyar and his clan are also credited[who?] to have "authored" many mantras of the Rig Veda, the earliest and most revered Hindu scripture, in the sense of first having the mantras revealed in his mind by the Supreme Brahman. Agasthiyar is also the author of Agasthiyar Samhita[ref: Dharma Bharathi]. In some reckonings, Agasthiyar is the greatest of the Seven Sages or Saptarshis.
The word is also written as Agasti and Agathiyar. A-ga means a mountain, Asti, thrower. Also a name of Shiva. Agasthiyar the Muni, was born of both Gods, Mitra and Varuna, from Urvashi. Agasthiyar is also the Indian astronomical name of the star of Canopus, is said to be the 'cleanser of waters', since its rising coincides with the calming of the waters of the Indian Ocean.
One story about Agastya goes that once the Kalakeyas (a clan of Asuras) had taken refuge in the Cosmic Ocean, so that it was difficult for the Devas to vanquish them, due to which they went to Sage Agasthiyar for help. After hearing the Devas, the sage drank the entire ocean water and held it within him, until the demons were destroyed.
In his book, he gives description of, and instructions for the creation of medicines for fever (it may be of any type), cancer, treatments for impotence, abdominal problems, brain and eye problems, bone problems, etc. Reputedly, his medicines give quick results without any side effects.
Another legend is about how Sage Agasthiyar saved the then Bharatavarsha from imbalance. Mount Vindhyachal continually grew in size due to taunting comments by Sage Narada according to a tory in the Shri Rama-Charitra-Manasa. So as to temper the vanity of the mountains, Sage Agasthiyar and his family traveled to South India, via the Mount Vindhyachal. On their way, when the Vindhyas saw Sage Agasthiyar, he bowed with respect and reverence, upon which Sage Agasthiyar played a trick on the Vindhyas, joking if he would stay bowed and subdued with respect till the sage returned. The Vindhyas was truly benevolent and promised to not grow until the seer's return from the South. After passing through the mountain, sage Agasthiyar told his wife, that they would never go back North side of mount Vindhyas ever again.
It is also believed by some that the Tamil language was taught to Sage Agasthiyar by Lord Shiva Himself.
He is considered as the first and foremost Siddha. He is considered the guru of many other Siddhas. He is also called Kurumuni, meaning short (kuru) saint (muni). He made contributions to the field of Medicine and Astrology - especially Nadi astrology. He is said[Tamil sidhhars] to have lived for over 5000 years, and that one of his medicinal preparations, Boopathi Kuligai, is so powerful that it can even bring the dead back to life. Two of his students and disciples were Therayar and Tholkappiar.
Another story about him is that once when the great sage accompanied by his beloved royal wife were wandering through forests, she fainted due to the humidity and hot conditions prevailing in the south. She was royal, hence not exposed to hard conditions. By seeing this the great sage became angry and prepared to punish the Sun God with his bow and arrows. Upon seeing this the sun god feared and appeared before Agasthiyar and presented him with umbrella and chappals (foot wear).
At a Saivite temple named Kutralam, formerly a Vishnu temple, in Tamil Nadu, Agasthiyar, in one legend, was refused entry. He then appeared as a Vaishnavite devotee and is said to have miraculously converted the image to a Shiva linga. A symbolic meaning of this conversion is to show that Vishnu and Shiva are different aspects of the one and same God.
The Dr. reveals for the first time the parental heritage of the sage. Sage Agathiyar was said to have been born about 4573 years prior to the commencement of Kali Yuga at a place in Gujarat, in the early hours of Tuesday, 14th of February 7673 BC. Belonging to the early Aryan race, his father Bhargava was well learned while his mother Indumathi was from Punjab. They were both devotees of the Pasupatha order of the sage Rishabha Muni.
Agathiyar then had his early education in Gujarat. As his thirst for knowledge in particular on philosophy, yoga, medicine, and astronomy was immense he traveled all over Kashmir, Tibet, China, Nepal and Kailas in Manchuria. Mount Kailas was deemed to be in Manchuria those days. He became a disciple of sage Nandi and Dhanvantri. He then traveled towards the south to Cambodia and Malaya. In Cambodia he established the very first of his many educational institutions for the propagation of philosophy and science.