金剛般若經疏論纂要 1.177

1.177

論云「前已說喻，何故復說？」偈云：「說多義差別，亦成勝校量，後福過於前，故重說勝喻。」何故不先說此喻？為漸化眾生令信上妙義故，又前未顯以何等勝功德能得菩提故。

The commentary says: "Since the simile was already spoken previously, why is it spoken again?" A verse says: "Explaining the differences among many meanings / Also establishes superior comparison; / Since the subsequent merit exceeds the former, / The superior simile is spoken again." Why was this simile not spoken first? In order to gradually transform sentient beings and make them have faith in the supreme and wondrous meaning; furthermore, previously it had not yet been revealed by what kind of superior merit bodhi can be attained.