金光明經文句記 6.41

6.41

二、依佛法。三時三月以為其本，各攝一月，故云三三本攝。二釋妨既三為一數，是故俗法及以佛法皆約三論。但以俗法本之與攝秖在三中，故名三三本攝。若佛法者，即以三三為能攝本，乃以三一為所攝月，亦得名為三三本攝。

Second, relying on Buddhist methods. Taking the three seasons and three months as their root, each subsuming one month, it is therefore called the three sets of three subsuming the root. Second, resolving objections: since three constitutes one count, both secular methods and Buddhist methods are discussed in terms of three. However, with secular methods, the root and the subsumed remain entirely within the three; hence it is called the three sets of three subsuming the root. As for Buddhist methods, the three sets of three serve as the subsuming root, while the three sets of one serve as the subsumed months; this may also be called the three sets of three subsuming the root.