大乘起信論裂網疏 6.37

6.37

此次揀能觀之心也。前云不依氣息乃至不依見聞覺知，即是一切分別想念皆除也。然所謂不依氣息等者，直是了達氣息乃至見聞覺知本不可得，除此分別氣息乃至覺知之想念耳，非謂果有氣息乃至覺知，而作意蠲除之也。若有蠲除之想，即是不達諸法本空，或墮外道無想定中，或墮二乘滅盡定中，非是大乘奢摩他觀，故云亦遣除想。

This next eliminates the contemplating mind. The previous statement that one does not rely on breath up to seeing, hearing, perceiving, or knowing means that all discriminative thoughts are eliminated. However, so-called not relying on breath and so forth simply means thoroughly understanding that breath up to seeing, hearing, perceiving, and knowing are originally ungraspable, eliminating these discriminative thoughts of breath up to perceiving and knowing; it does not mean that there really is breath up to perceiving and knowing and that one intentionally dispels them. If one has the thought of dispelling, that is failing to understand that all dharmas are originally empty, and one will either fall into the non-conceptual concentration of external paths or the concentration of cessation of the two vehicles, which is not Mahāyāna śamatha contemplation; thus it says 'the thought of eliminating is also discarded'.