金剛般若波羅蜜經註解 1.73

1.73

佛告善現：「應如是不住於相而行施」者，蓋欲菩薩降伏妄心也。

When the Buddha tells Subhūti, 'One should practice giving in this way without abiding in marks,' it is because he wishes for bodhisattvas to subdue their deluded minds.