大般涅槃經義記 7.407

7.407

「若心無」下第三復次，舉脫顯有。「若心無貪，如來云何說心解脫」，說心脫故，明貪實有。

From "If the mind lacks" onward is the third point, which adduces liberation to reveal existence. "If the mind lacks greed, how could the Tathāgata speak of the mind's liberation?" Because he speaks of the mind's liberation, it is clear that greed genuinely exists.