妙法蓮華經玄贊 2.224

2.224

贊曰：此釋其意。放光何意？欲令聞知難信法故。昔說二真、今談一實，令捨舊極取今新極，故名難信。不但信難，義旨亦難。

Commentary: This explains its meaning. What is the intent of emitting the light? He wishes to cause them to hear and know the Dharma that is difficult to believe. Formerly he taught two truths, but now he discusses the single reality, causing them to abandon the old ultimate and adopt the new ultimate; therefore it is called “difficult to believe.” Not only is faith difficult, the doctrine and purport are also difficult.