Maha Kaccana: Master of Doctrinal Exposition Katyayana or Mahakatyayana, also known as in Pali Kaccana (or Kaccayana), or Mahakaccana, in Japanese as Kasennen and in Thai he is called Phra Maha Katchaina was listed as one of the "ten principal disciples" of Gautama Buddha. He was foremost in explaining Dharma.
Kātyāyana was born in a Brahmin family at Ujjayini and received a classical Brahminical education studying the Vedas. Katyayana studied assiduously under Asita on Mount Vindhya, who had predicted that Prince Siddharta would become either a cakravartin, a great worldly ruler, or a Buddha.
Kancana replaced his father as court chaplain.The king whom he served was known as Candapajjota heard that a Blessed One had arisen in the world, a desire arose in him to see the Buddha. He requested his chaplain to invite the Buddha to Avanti as his guest. Kancana agreed to invite the Buddha if the King gave him permission to be ordained as a monk.
With the king’s permission Kancana and seven other courtiers left Avanti and set out for Savatthi, where the Buddha was residing. Inspired by the Buddha’s teaching, all eight attained Arahanthship together with the four analytical knowledges and were ordained as monks. Kancana was known as Kaccana after ordination. Kaccana enumerated the scenic beauty of Ujjeni to the Buddha, with the intention of inviting Him to visit Avanti. The Buddha, realizing that Kaccana was quite capable of inspiring the king, his ministers and townsfolk, asked Kaccana to return to Avanti with the former courtiers.
He preached constantly to the people, and, attracted by his discourses, numerous persons joined the Order, so that the whole city was one blaze of orange robes. It is said that after having duly established the sásana in Avantí, Kaccána returned once more to the Buddha.
Kaccana’s analytical, organised mind and his ability to penetrate the Dhamma and then simplify the message in a manner that was easy to understand helped him to assist many novice monks and lay devotees to understand the complex teachings. His skills helped many of the less spiritually advanced to grasp the deep teachings of the Buddha. Maha Kaccana made an invaluable contribution to the preservation of the Dhamma. His lucid explanations of deep subjects have been carefully documented and as such helped not only the contemporaries of the Buddha but following generations. The text documents well his role as a great teacher. His primary role, however, was to elaborate on the statements made by the Buddha. Maha Kaccana was declared by the Buddha to be foremost among the monks who explained in detail brief statements proclaimed by the Buddha. Kaccana was known as Maha Kaccana to distinguish him from other monks who had the same Brahmanic name.