法華論疏 2.465

2.465

經中稱之為入、論稱為之證也，以入即是證。令不退轉者，既證法身便不退轉。

In the sūtra, it is called "entering"; the treatise calls it "realizing," because entering is precisely realizing. "Causing them not to retrogress": once they have realized the dharmakāya, they do not retrogress.