俱舍論疏 9.156

9.156

論「若爾便應成至不成釋難」，論主破也。豈由理證知即經不說？若爾，十二緣起皆理可證，何為緣起經中唯說十二，不說無明之因老死之果？

On the Śāstra's statement: 'If so, then it would follow that, up to: it would not constitute an explanation of the objection': the author of the Śāstra refutes this. Can it be that simply because something is known through reasoning, the sūtra does not state it? If so, all twelve [links of] conditioned origination can be established by reasoning; why then does the sūtra on conditioned origination speak only of the twelve, and not speak of the cause of ignorance nor of the result of old age and death?