Brahmajalasutta 2.21.2

2.21.2

Ye hi keci, bhikkhave, samaṇā vā brāhmaṇā vā antānantikā antānantaṃ lokassa paññapenti, sabbe te imeheva catūhi vatthūhi, etesaṃ vā aññatarena; natthi ito bahiddhā.

Any ascetics and brahmins who assert that the cosmos is finite or infinite do so on one or other of these four grounds. Outside of this there is none.