俱舍論疏 23.39

23.39

論「後增進時具四念住」，釋安足後，下，中，上中，或唯觀色、或唯觀受、或復總觀，皆無遮也。

[On] the treatise's: "When subsequently advancing, they possess all four applications of mindfulness", this explains that after establishing a foothold, whether in the lower, intermediate, or upper [grades], whether contemplating only form, or contemplating only sensation, or universally contemplating again, none are precluded.