妙法蓮華經文句 1.163

1.163

觀心者，觀五陰舍析空即空，與化佛同宿；觀五陰舍即假，與報佛同宿；觀五陰舍即中，與法佛同宿（云云）。

Regarding contemplation of mind: contemplating the dwelling of the five aggregates as empty by analysis is identical to emptiness, lodging together with the transformation Buddha; contemplating the dwelling of the five aggregates as identical to the provisional, lodging together with the reward Buddha; contemplating the dwelling of the five aggregates as identical to the middle, lodging together with the Dharma Buddha, and so forth.