摩訶止觀 1.16

1.16

云何「圓行」？一向專求無上菩提，即邊而中，不餘趣向，三諦圓修。不為無邊所寂、有邊所動，不動不寂直入中道，是名「圓行」。

What is "perfect practice"? Exclusively and single-mindedly seeking unexcelled bodhi; identifying extremes as the middle, not heading toward anything else; cultivating the three truths in their perfection. Neither stilled by the extreme of non-existence nor moved by the extreme of existence, unmoved and unstilled, one enters straight into the middle way—this is named "perfect practice."