The Long Āgama Sūtra 21.23

21.23

「或有眾生展轉相看已，便失意，由此命終，來生世間，漸漸長大，剃除鬚髮，服三法衣，出家修道，入定意三昧，以三昧心識本所生，便作是言：『如彼眾生以不展轉相看，不失意故，常住不變；我等於彼數相看，數相看已便失意，致此無常，為變易法，我以此知：我及世間半常半無常，此實餘虛。』是第三見。諸沙門、婆羅門因此於本劫本見起論：我及世間半常半無常。於四見中，齊此不過。

“Some sentient beings forget themselves after watching each other one after the other. As a result, they’re born in the world when their lives end. They gradually grow up, shave their hair, put on the three Dharma robes, leave home, and cultivate the path. They enter a samādhi of mind through which they became aware of their past births. Then they say, ‘Those sentient beings that don’t forget themselves while watching each other one after the other are everlasting and unchanging. We frequently watched each other and forgot ourselves after doing so. As a result, we’ve come to this impermanent state that’s subject to change. Therefore, I know: “Self and the world is half eternal and half impermanent. This is true; the rest is false.”’ This is the third view. As a result of creating this theory about past eons [that self and world are] half eternal and half impermanent, ascetics and priests don’t go beyond these four views.