俱舍論記 9.135

9.135

「若緣起支至成無窮失」者，此下第五釋通疑難。此即敘疑。若無果因，應有終始。若更立支，成無窮失。

Regarding "If the links of dependent origination [...] there would be the fault of infinite regress": from this point on is the fifth section, resolving doubts and objections. This introduces the doubt: if there are no fruits or causes, there should be an end and a beginning; if further links are established, there would be the fault of infinite regress.