摩訶止觀 2.65

2.65

又觀一運心十法具足。一不定一，故得為十；十不定十，故得為一。非一、非十，雙照一十，一念心中具足三諦。住、坐、臥、語、默，作作亦復如是，準前可知。故《法華》云：「又見佛子，名衣上服以用布施，以求佛道。」即此義也。

Furthermore, one contemplates that a single phase of the moving mind is fully endowed with the ten dharmas. The one is not definitively one, and therefore can be ten; the ten are not definitively ten, and therefore can be one. It is neither one nor ten, yet both illumination of the one and the ten. Within a single thought-moment of mind, the three truths are fully present. Standing, sitting, lying down, speaking, keeping silent—every single action is also like this, as can be known by following the preceding. Therefore, the Lotus Sūtra says: 'Again I see the Buddha's sons / giving fine robes and superior clothing / to seek the Buddha path.' This is precisely the meaning.