妙法蓮華經玄贊 10.396

10.396

釋名者，在俗皇貴，妙珍綺以飾容；迴邪入正，勝法寶而瑩體，故名妙莊嚴王。宿世因緣，故名本事。

Regarding explaining the title: In worldly status, imperial and noble, he used wonderful gems and brocades to adorn his countenance; turning from heterodoxy to enter the right, he used the superior jewel of the Dharma to lustrate his body; hence he is named King Śubhavyūha (“Wonderful Adornment”). As these are conditions from past lives, it is termed “Ancient Accounts” (pūrvayoga).