坐禪三昧經 1.32

1.32

若思覺偏多，當習阿那般那三昧法門。有三種學人：或初習行、或已習行、或久習行。若初習行，當教言一心念數，入息出息，若長若短，數一至十。若已習行，當教言數一至十，隨息入出，念與息俱，止心一處。若久習行，當教言數、隨、止、觀、轉觀、清淨。阿那般那三昧，六種門十六分，云何為數？一心念入息，入息至竟數一，出息至竟數二。若未竟而數為非數，若數二至九而誤，更從一數起。譬如算人，一一為二、二二為四、三三為九。

If discursive thought is predominantly excessive, one should practice the dharma gate of the ānāpānasmṛti samādhi. There are three types of trainees: those who are beginners in practice, those who have already practiced, and those who have practiced for a long time. If one is a beginner in practice, one should be instructed to single-mindedly count, whether inhalation and exhalation are long or short, counting from one to ten. If one has already practiced, one should be instructed to count from one to ten, follow the breaths as they enter and exit, keeping mindfulness alongside the breath, and bring the mind to rest in one place. If one has practiced for a long time, one should be instructed in counting, following, resting, contemplating, transformative contemplation, and purification. In the ānāpānasmṛti samādhi there are six gates and sixteen divisions. What is counting? One single-mindedly is mindful of the inhalation; when the inhalation has fully ended, one counts 'one'; when the exhalation has fully ended, one counts 'two'. If one counts before it is finished, that is non-counting; if while counting from two to nine one makes an error, one begins counting over again from 'one'. It is just like an accountant: one times one is two, two times two is four, three times three is nine.