The Long Āgama Sūtra 7.41

7.41

答曰：「迦葉！我有親族，遇患篤重，我往語言：『沙門、婆羅門各懷異見，說有後世，言不殺、不盜、不婬、不欺、不飲酒者，身壞命終，皆生忉利天上；我亦不信，所以然者？初未曾見死已來還，說所墮處；若有人來說所墮生，我必信耳。今汝是我所親，五戒具足，身壞命終，必生忉利天上，今我相信，從汝取定，若審有天福者，汝當還來，語我使知，然後當信。』迦葉！彼命終已，至今不來，彼是我親，不應有欺，許而不來，必無他世。」

He answered, “Kāśyapa, I had a relative who fell seriously ill. I went and said to him, ‘Ascetics and priests each hold unorthodox views. They say that someone who doesn’t kill beings, steal, engage in sex, lie, or drink alcohol will be born in Heaven when their body breaks up and their life ends. I don’t believe this, either. Why is that? To begin with, I’ve never seen anyone return after dying, though it’s claimed they fall somewhere. If someone were to come back and say where they fell, I would certainly believe it. Now, you are a friend of mine who has completed the five precepts … you’d surely be born in Heaven when your body breaks up and your life ends. We trust each other, and I’d certainly accept what I heard from you. If you discover there is a heaven, you should return and tell me about it. Then, I’ll believe it.’

“Kāśyapa, my relative hasn’t come back since their life ended. They were my friend; they wouldn’t have lied to me. They agreed, but they didn’t come back. Surely, there isn’t another world.”