SN20.7 — The Discourse on the Peg - Āṇi Sutta
At Sāvatthī. Disciples, there was once a drum called Summoner belonging to the Dasārahas. When the Summoner drum was cracked, the Dasārahas inserted another peg. There came a time when the original drumhead of the Summoner disappeared, leaving only a mass of pegs.
In the same way in the future there will be disciples who, when those discourses spoken by the Tathāgata: deep, profound in meaning, transcendent, connected with emptiness: are being recited, will not listen, will not lend an ear, will not apply their minds to understand them, and will not think those teachings should be learned and mastered.
But when those discourses that are poetically composed, with elegant words and phrases, created by poets, spoken by disciples, are being recited, they will listen, lend an ear, apply their minds to understand them, and think those teachings should be learned and mastered.
Thus there will be a disappearance of those discourses spoken by the Tathāgata: deep, profound in meaning, transcendent, connected with emptiness.
Therefore you should train yourselves thus: When those discourses spoken by the Tathāgata: deep, profound in meaning, transcendent, connected with emptiness: are being recited, we will listen, lend an ear, apply our minds to understand them, and think those teachings should be learned and mastered.
Thus should you train yourselves, disciples.