瑜伽論記 6.483

6.483

所知事者已下，生前聞思本所知事，謂即五停心觀，五善巧，六行觀，四諦，名為所知。

From 'knowable phenomena' downward, it generates the original knowable phenomena of the preceding hearing and thinking, namely, the five meditations for calming the mind, the five skills, the six-aspect contemplation, and the four truths; these are called the knowables.