金剛經纂要刊定記 4.32

4.32

依止差別者。依止即是眾生身，身具依止，依止義異，故云差別。故疏次云：「有色無色等。」有色即以色為身，無色即以四蘊為身。又色界有四禪云云，無色有四空云云，如是品類不同，故云依止差別。

Regarding "distinctions in support": "support" refers to the body of sentient beings. The body possesses support, and because the meanings of support differ, it is called "distinctions." Therefore the commentary next says: "with form, formless, etc." "With form" means taking form as the body; "formless" means taking the four aggregates as the body. Furthermore, the form realm has the four dhyānas, and so on, while the formless realm has the four immaterial attainments, and so on; because classes such as these are not the same, it is called "distinctions in support."