無量壽經優婆提舍願生偈註 2.177

2.177

出第五門者，以大慈悲觀察一切苦惱眾生，示應化身，迴入生死園煩惱林中遊戲神通，至教化地，以本願力迴向故，是名出第五門。

As for exiting through the fifth gate: by contemplating all suffering sentient beings with great compassion, manifesting responsive transformation-bodies, returning to the garden of birth-and-death and the grove of afflictions to sport with spiritual powers, and arriving at the ground of teaching and transforming through dedication of merit by the power of the fundamental vow; this is called exiting through the fifth gate.