妙法蓮華經玄義 5.71

5.71

開生死麁心者，明凡夫有反復，易發菩提心。生死即涅槃，無二無別，即麁是妙也。若始從凡夫，發析、體、別、圓四心者，亦是四位初心。皆是因緣所生心，即此因緣，即空、即假、即中，與圓初心無二無別。諸初心是乳顯妙，即是置毒乳中，即能殺人。殺有奢促，若按位而妙，即成假名妙。若進入方便，成相似妙。若進入理，即成分真妙（云云）。

Opening the coarse mind of saṃsāra explains that ordinary beings have the capacity to turn back, making it easy for them to generate the bodhicitta. Saṃsāra is precisely nirvāṇa, without duality and without difference; the coarse is itself the subtle. If, beginning from an ordinary being, one generates the four minds of analyzing, embodying, distinctive, and perfect, these are also the initial minds of the four stages. All are minds produced by causes and conditions; these very causes and conditions are identical to emptiness, identical to the provisional, and identical to the middle, without duality or difference from the initial mind of the perfect [teaching]. These various initial minds are revealing the subtle from milk; this is placing poison in milk, which can then kill a person. In killing there is slow and fast: if it is subtle according to its stage, it then constitutes the nominal subtle; if one advances into expedients, it constitutes the semblance subtle; if one advances into the principle, it constitutes the partial-realization subtle, and so forth.