"For a disciple who has conviction in the Teacher's message & lives to penetrate it, what accords with the Dhamma is this: 'The Blessed One is the Teacher, I am a disciple. He is the one who knows, not I.'
Majjhima Nikāya 70
“It is impossible, it cannot happen that a person possessing right view could acknowledge another teacher - there is no such possibility.”
Bahudhātuka Sutta, Majjhima Nikāya 115
"In the same way, in the course of the future there will be monks who won't listen when discourses that are words of the Tathagata — deep, deep in their meaning, transcendent, connected with emptiness — are being recited. They won't lend ear, won't set their hearts on knowing them, won't regard these teachings as worth grasping or mastering. But they will listen when discourses that are literary works — the works of poets, elegant in sound, elegant in rhetoric, the work of outsiders, words of disciples — are recited. They will lend ear and set their hearts on knowing them. They will regard these teachings as worth grasping & mastering.
"In this way the disappearance of the discourses that are words of the Tathagata — deep, deep in their meaning, transcendent, connected with emptiness — will come about.
SN 20.7
These five things lead to the continuation, persistence, and enduring of the true teaching. What five? It’s when mendicants carefully listen to the teachings, memorize them, and remember them. They carefully examine the meaning of teachings that they remember. And they carefully practice in line with the meaning and the teaching they’ve understood. These five things lead to the continuation, persistence, and enduring of the true teaching.”
Paṭhamasaddhammasammosa Sutta AN 5.154
These five things lead to the continuation, persistence, and enduring of the true teaching. What five? It’s when the mendicants memorize the teaching— statements, songs, discussions, verses, inspired sayings, legends, stories of past lives, amazing stories, and analyses. This is the first thing that leads to the continuation, persistence, and enduring of the true teaching.
Furthermore, the mendicants explain the teaching in detail to others as they learned and memorized it. This is the second thing …
Furthermore, the mendicants make others recite the teaching in detail as they learned and memorized it. This is the third thing …
Furthermore, the mendicants recite the teaching in detail as they learned and memorized it. This is the fourth thing …
Furthermore, the mendicants think about and consider the teaching in their hearts, examining it with their minds as they learned and memorized it. This is the fifth thing that leads to the continuation, persistence, and enduring of the true teaching. These five things lead to the continuation, persistence, and enduring of the true teaching.”
Dutiyasaddhammasammosa Sutta AN 5.155
These five things lead to the continuation, persistence, and enduring of the true teaching. What five? It’s when the mendicants memorize discourses that have been learned correctly, with well placed words and phrases. When the words and phrases are well organized, the meaning is correctly interpreted. This is the first thing that leads to the continuation, persistence, and enduring of the true teaching.
Furthermore, the mendicants are easy to correct, having qualities that make them easy to correct. They’re patient, and take instruction respectfully. This is the second thing …
Furthermore, the mendicants who are very learned—knowledgeable in the scriptures, who have memorized the teachings, the texts on monastic training, and the outlines—carefully make others recite the discourses. When they pass away, the discourses aren’t cut off at the root, and they have someone to preserve them. This is the third thing …
Furthermore, the senior mendicants are not indulgent and slack, leaders in backsliding, neglecting seclusion. They rouse energy for attaining the unattained, achieving the unachieved, and realizing the unrealized. Those who come after them follow their example. They too are not indulgent or slack … This is the fourth thing …
Furthermore, the Saṅgha lives comfortably, in harmony, appreciating each other, without quarreling, with one recitation. When the Saṅgha is in harmony, they don’t abuse, insult, block, or reject each other. This inspires confidence in those without it, and increases confidence in those who have it. This is the fifth thing that leads to the continuation, persistence, and enduring of the true teaching. These five things lead to the continuation, persistence, and enduring of the true teaching.”
Tatiyasaddhammasammosa Sutta AN 5.156