瑜伽論記 7.166

7.166

泰師云：前句辨由後二瑜伽為首前起，故令初二轉依義成，後句辨由轉依清淨為依首，故令後二瑜伽得清，於其轉所成辨時後二瑜伽轉起。

Master Tai says: The former clause explains that because the latter two yogas precede and act as foremost, the meaning of the initial two revolutions of the basis is accomplished; the latter clause explains that with the purification of the revolution of the basis as the foremost support, the latter two yogas are made pure; when what is transformed accomplishes its task, the latter two yogas operate and arise.