瑜伽論記 7.58

7.58

謂言若是處轉者，牒結上以一為一等四種算數之義也。若乃至轉者，結上勝進算數也。若如所轉者，結上錯亂應退還從一起。若時而轉者，結上若時算數極串習故知有知無等。於此一切，由安住念等者，結上如是展轉相續流注乃至令心安住等也。泰云：諸孔穴處名若是處轉，入身乃至臍輪名乃至轉，如出入息名若如所轉，出入息相續長短時分名若時而轉。

Regarding 'wherever it operates': this recapitulates and concludes the meaning of the four kinds of counting above, such as counting one as one; 'up to however it operates' concludes the progressive counting above; 'as it operates' concludes that upon confusion one should regress and start from one again; 'at whatever time it operates' concludes that when counting is extremely well practiced, one knows presence and knows absence, etc.; regarding 'in all these, due to mindfulness being stably positioned', etc., it concludes the statement 'thus sequentially and continuously flowing up to causing the mind to abide stably', etc. Tai says: 'The various apertures are called "wherever it operates"; entering the body down to the navel-wheel is called "up to however it operates"; conforming to the in-and-out breaths is called "as it operates"; the successive long or short durations of the in-and-out breaths are called "at whatever time it operates".'