瑜伽論記 1.50

1.50

釋論解云：三乘行者，由聞思等，次第習行，如是瑜伽，隨分滿足，展轉調化諸有情，故名瑜伽師。或諸如來，證瑜伽滿，隨其所應，持此瑜伽，調化一切聖弟子等，令其次第修正行，故名瑜伽師。

The Commentary explains: Practitioners of the three vehicles gradually cultivate and practice such yoga through hearing, thinking, and so forth, fulfilling it according to their lot, and in turn train and transform sentient beings; thus they are named yoga masters. Alternatively, the Tathāgatas, having completely realized yoga, maintain this yoga as appropriate and train and transform all noble disciples and so forth, causing them to gradually cultivate correct practice; thus they are named yoga masters.