首楞嚴義疏注經 1.342

1.342

若汝堅執無體能合，十九界、第七塵體畢竟無，亦應有合。世間學者誰信有之？故云不然。

If you stubbornly maintain that what has no substance can unite, then a nineteenth realm and a seventh dust, whose substances are utterly non-existent, should also unite. Who among the scholars of the world would believe that such exist? Therefore he says it is incorrect.