仁王經疏 2.189

2.189

釋曰：第七、入理不動。謂入理時，非分別所動，故名不動。或不退故，名而不動。

Commentary: Seventh, entering the principle and remaining unmoving. That is, when entering the principle, they are not moved by discrimination; hence it is called "unmoving." Or, because they do not retrogress, it is called "unmoving."