無量壽經優婆提舍願生偈註 2.110

2.110

上言不動而至，容或至有前後，是故復言一念一時無前後也。

Above it was said that they reach [all places] without moving, but perhaps their arrival might occur earlier or later; therefore it is further said: 'In a single thought-moment and at the same time,' with neither earlier nor later.