金剛經纂要刊定記 4.39

4.39

問：「下二界皆有色，何故唯言四禪以為色界？又色界亦有一天名為無想，云何唯指無所有處為無想耶？」

Question: "The lower two realms both have form; why does it speak only of the four dhyānas as the form realm? Furthermore, the form realm also has a heaven named 'Non-Perception' (asaṃjñin); why does it point solely to the station of nothingness as non-perception?"