仁王護國般若波羅蜜多經疏 2.78

2.78

解曰：即此文字所詮顯也。般若空故者，境智空也。菩薩亦空者，能行照者菩薩亦空。從此第二徵其所以。

Exposition: This is what is expressed and revealed by these letters. "Because prajñā is empty" means that object and cognition are empty. "The bodhisattva is also empty" means that the bodhisattva who can practice and contemplate is also empty. Next is the second: inquiring into its reason.