首楞嚴義疏注經 3.154

3.154

破即心也。初一句牒，次一句定，非心下破。既即是心，定非是塵；若非是塵，則不是心家所緣之境，何名法處？下破離心。

Refuting their being identical to the mind. The first line cites [the assertion], the next line determines [it], and from 'not an object' onward refutes it. Since they are identical to the mind, they are definitely not sense-dust; if they are not sense-dust, they are not an objective realm grasped by the mind; how can they be called the āyatana of dharmas? Below refutes their being apart from the mind.