摩訶止觀 2.63

2.63

次、觀六作行檀者，觀未念行、欲行、行、行已，四運遲速皆不可得，亦不見不可得。反觀覺心，不外來、不內出、不中間、不常自有，無行、無行者，畢竟空寂。

Next, regarding contemplating the six activities as practicing dāna (giving): one contemplates [the act of] walking in four phases of movement—not yet thinking of walking, wishing to walk, walking, and having walked. Their slowness or swiftness is entirely ungraspable, nor does one perceive anything ungraspable. Turning back to contemplate the aware mind: it does not come from without, does not emerge from within, does not exist in between, and does not permanently exist of itself. There is no walking and no walker; it is completely empty and quiescent.