妙法蓮華經玄贊 10.91

10.91

釋名者，「常」者恒義，「不輕者」恭敬義。觀他四眾具佛性因，勸他修行必得作佛，三業恒時虔恭敬仰，故名常不輕。

Explaining the title: 'Sadā' ('Ever') means constant. 'Aparibhūta' ('Never Slighting') means reverent respect. Seeing that the other four assemblies are endowed with the cause of buddha-nature, he exhorts others to practice and that they will surely become buddhas; in the three karmic modes, he constantly offers devout homage and reverent admiration; hence he is named Sadāparibhūta.