俱舍論記 4.69

4.69

「有雖難了至而不乖反」者，復難。世間諸物有雖難了，由審推度而復可知。此捨、作意最難了知，謂有警覺及無警覺二相違背，而不乖反一心中起。

Regarding "Although some are difficult to discern, ... yet they do not contradict each other": Another objection. Although some things in the world are difficult to discern, they can nevertheless be known through careful deliberation. These two, equanimity and attention, are the most difficult to discern: namely, having alertness and lacking alertness are mutually opposed, yet they arise in a single mind without contradicting each other.