摩訶止觀 6.20

6.20

先緣識多，定心分散；捨多識緣，無所有識。若緣少識，豈得名「無所有」耶？則是用少識，豈得名「不用處」耶？今緣無所有入定，此法與心相應，亦具三假等，亦用四觀。餘例可知。

Initially taking consciousness as the object is predominant, so the concentrated mind is scattered; relinquishing the focal condition of multiple consciousnesses, there is the consciousness of nothingness. If one were to take a meager consciousness as the object, how could it be named "nothingness"? That would be using a meager consciousness; how could it be named "the sphere of non-use"? Now, taking nothingness as the object to enter concentration, this dharma corresponds with the mind and also possesses the three provisionalities and so forth; one also uses the four contemplations. The rest can be understood by analogy.