妙法蓮華經玄贊 4.53

4.53

Hindrance has the meaning of obstruction; all three are obstructions because they obstruct the noble path. Defilement has the meaning of dregs and impurity; because the defiling aspect of karma is subtle, it is not established as a defilement. Furthermore, the weapons during a kalpa are precisely the defilement of karma; because the defilement of the kalpa is broad, it takes its name from the broader category; establishing it this way is also without error.