俱舍論頌疏論本 1.142

1.142

釋曰：總攝一切法，由一蘊處界者，正明相攝。攝一切法，由一色蘊、由一意處、由一法界。所以者何？且一切法不過五位：一色、二心、三心所、四心不相應、五無為法。一切色法一色蘊攝盡，一切心法一意處攝盡，一切心所及不相應并無為法一法界攝盡，故舉此三攝法總盡。

The commentary explains: 'All dharmas are fully subsumed / by one skandha, āyatana, and dhātu' directly explains mutual subsumption. All dharmas are subsumed by one rūpa-skandha, one manas-āyatana, and one dharma-dhātu. Why is that? All dharmas do not exceed five categories: first, form; second, mind; third, mental factors; fourth, mental non-concomitants; fifth, unconditioned dharmas. All form dharmas are entirely subsumed by the one rūpa-skandha; all mind dharmas are entirely subsumed by the one manas-āyatana; all mental factors, non-concomitants, and unconditioned dharmas are entirely subsumed by the one dharma-dhātu. Therefore, by presenting these three, dharmas are completely subsumed.