金剛經纂要刊定記 5.140

5.140

相續忍。經意云：恐人將謂只是一度能為此忍，故說過去已五百生。或恐人言：無我能忍應可暫時，若使頻為必不能爾。故說多生悉皆如是。或恐人言：有何所因無我能忍？故說多生忍之熟故。含三意故，有是言也。

Continuous forbearance: The intention of the sūtra is that, fearing people would think he was able to practice such forbearance only once, it therefore speaks of the past five hundred births. Or fearing people would say: "Being able to endure through selflessness might be possible temporarily, but if made to do so repeatedly, one certainly could not do so," it therefore says that through many births it was entirely like this. Or fearing people would say: "By what cause could one endure through selflessness?" it therefore says that through many births forbearance had matured. Because it encompasses these three intentions, there is this statement.