瑜伽論記 8.425

8.425

第三、因力，宿習大乘善法者，由宿習力暫見佛等即能發心，名為因力。

The third is the power of the cause: one who has habitually cultivated the wholesome dharmas of the Mahāyāna in the past, through the power of past cultivation, temporarily seeing a Buddha or the like, is immediately able to generate the mind; this is called the power of the cause.