The Bhikkhu Subhadda, a recluse, said that the Buddha demised (entered the Parinibbana) so we do not need to follow the rules which were laid down by the Buddha. Ashin Mahakassapa Mahathera remorsed about the speech of the recluse. Therefore, Ashin Mahakasappa Mahathera exhorted to hold the First Buddhist Council. “Handa Mayam avuso dhammanca Sangayissama, Pure adhammo dibbati, dhammo patibahiyyati, pure avinayo dibbati, vinayo patibahiyyati, Pure adhammavadino balavanto honti, vinayavadino dubbala honti. (Vi-4, 481, VI, tha, 1; 6) 

Ashin Mahakassapa Mhathera preached as follow:

”O Bhikkhu! Before the Adhammavada which is not the Teaching of the Buddha would strengthen; before the Dhamma, the Teaching of the Buddha would be forbidden; before the wrong disciplines (Vinaya) would prevail; before the right disciplines (Vinaya) would be forbidden; before the persons who are Adhammavadi (Micchaditthi) would strengthen; before the persons who are Dhammavadi (Right persons) would become weaker; before the Bhikkhus who do not practise laws or disciplines (Vinaya) would strengthen; before the Bhikkhus who do practise laws or disciplines (Vinaya) would become weaker; Let us hold the First Buddhist Council in the Buddha^‘s Dhammavinaya.”

”Samgho apannattam nappannapeti, pannattam na samucchindati, yatha pannattesu sikkhapadesu samadaya vattati” (Vi, 4, 485)

Ashin Mahakassapa Mahathera laid down the policy thus: ”The Samgha do not lay down the laws or disciplines (Vinaya) which the Buddha had not laid down; do not reject the laws or disciplines (Vinaya) which the Buddha had laid down. We should practise in the following disciplines (Vinaya) which were laid down by the Buddha.” And the First Buddhist Council was held by the admonishment of Ashin Mahakassapa.

As Ashin Mahakassapa preached the Pitaka, the Dhamma Vinaya of the Buddha which contains Pali, Atthakatha, Tika, and these were collectively recorded by reciting from the First to the Six Buddhist Council is called ” Theravada Buddha Sasana.”