大乘入道次第開決 1.101

1.101

生具一切善根等者。由因善根諸願方滿。既善知識令我願滿。故知具足諸善根也。

Regarding "producing [the thought of] being endowed with all roots of goodness, etc.": because of the cause of roots of goodness, all vows are fulfilled. Since the spiritual friend causes my vows to be fulfilled, one knows that they are endowed with all roots of goodness.