六妙法門 1.71

1.71

復次，行者當數息時，發空無相智慧、三十七品、四諦、十二因緣等巧惠方便，思覺心起，破折諸法，反本還源，當知於數息中，證還門禪也。

Furthermore, when a practitioner is counting breaths, if the wisdom of emptiness and signlessness, the thirty-seven factors [of awakening], the four [noble] truths, the twelve links of dependent origination, and other skillful expedients arise, so that conceptual thought arises, breaking down all phenomena and returning back to the source, one should know that while counting breaths, he realizes the dhyāna of the gate of turning back.