成唯識論述記 2.109

2.109

述曰：下第三、顯極微非有實義，即是為執實法，實我是一、是常故，佛說極微，令其除執而分折色，非謂有實極微體，故佛說之也。然依他故，可說為實成所緣緣故，依所折色說故，然《瑜伽論》第五十四：由五緣故，佛說極微。

The Commentary states: Below is the third section, revealing that atoms are not real entities. That is, for the sake of those who cling to real dharmas and a real self as one and permanent, the Buddha taught atoms, causing them to eliminate attachment by dividing visible form, not that there is a real substance of an atom and therefore the Buddha taught it. However, because it is paratantra, it can be said to be real, establishing the condition as cognitive object, being spoken of on the basis of the divided form. Moreover, fascicle 54 of the Yogācārabhūmi states: based on five conditions, the Buddha taught atoms.