釋摩訶衍論 1.36

1.36

總攝門者，通攝一切十方界中所有眾生眾命根故，如本命盡十方故。

As for the gate of universally gathering, it is because it comprehensively gathers all the life-roots of sentient beings existing throughout all realms of the ten directions, as in the root text's “the lives [of all beings] throughout the ten directions.”