I am not sure whether there is a single sutta that says so.
- But the inference can be made by studying various relevant suttas. I will provide a few below. Perhaps others can add to this collection, and I can write a post. These issues keep coming up, so it would be good to have one post that summarizes what is in the suttas.
“Cūḷanikā Sutta (AN 3.80)“, “Rohitassa Sutta (SN 2.26)“, “Acinteyya Sutta (AN 4.77).”
- In the first one, the Buddha tells Ven. Ananda about the “mahāsahassī lokadhātu” (a region of space) with a billion stars with planetary systems like ours. As I understand, that is the “maximum range” of a single Buddha. But there can be many Buddhas even now, in other such “mahāsahassī lokadhātu” in the universe. Our Milky Way galaxy has 100 billion stars. Thus, even within our Milky Way galaxy, there could be living Buddhas right now. The English translation used the word “galaxy” for a collection of only 1000 planetary systems, which is wrong.
- There is also a sutta, which describes Ven. Moggalana took off to “look for the end of the world.” He got lost on the way, and the Buddha had to rescue him. I don’t remember the name of that sutta.
That is why, in the last sutta quoted above, the Buddha says figuring out the universe’s structure is “not achievable” for humans. Anyone who tries to do that “will go mad or get frustrated” (see the starting verse of that sutta).
