華嚴經義海百門 1.84

1.84

八、通逆順者，謂舉塵相不必見理，為逆；以塵無體即空，為順。由相取不可得，逆則常順；以理不礙事，順則常逆。由事理融通，是以逆順無礙，自在用也。

Eighth, penetrating the reverse and the direct: Bringing forth the characteristics of a dust mote without necessarily seeing the principle is the reverse; taking the dust mote as empty because it lacks essence is the direct. Because grasping at characteristics is unobtainable, the reverse is constantly direct; because principle does not obstruct phenomena, the direct is constantly reverse. Because phenomena and principle are fused and penetrating, the reverse and the direct are unobstructed, functioning freely.