成唯識論述記 4.387

4.387

述曰：破上異師別生解者，謂生無色初剎那後，彼時意識應永不生，初無意識，彼此同故。若彼伏言受生已，次入定無散意者，理亦不然，定心必由散意識引；或加行為因，如聞、思等；或生得善引生方起，此通三界。五識、他教此之二因，彼界無有，能引起定。散心意識，在彼界中無由起故，定如何生。非初受生即可得定，故彼三因彼初無有，彼界散意何緣得生。

The Commentary states: Refuting the different teacher above who generated a distinct understanding: that is, after the first moment of birth in the formless realm, mental consciousness at that time should never arise, because the initial absence of mental consciousness is identical between both [opinions]. If they secretly maintain that after taking birth, one immediately enters meditative concentration without distracted mind, this principle is also incorrect. A concentrated mind must be led by distracted mental consciousness, either caused by preparatory practice, like hearing and contemplating, or arising only after being induced by innate good; this applies generally to the three realms. The two causes of the five consciousnesses and instructions from others do not exist in that realm to be able to induce meditative concentration. In that realm, because distracted mental consciousness has no way to arise, how could meditative concentration arise? Meditative concentration cannot be obtained immediately upon taking birth; hence those three causes do not exist initially there, so by what condition could distracted mind arise in that realm?