成唯識論演祕 2.225

2.225

現行熏彼新熏種時，本有舊種亦復摶生一種子也，即是四法同時起也。此非正義。

At the time when the manifest activity perfumes that newly perfumed seed, the primordial old seed also produces a seed; that is to say, four dharmas arise simultaneously. This is not the orthodox doctrine.