法華論疏 2.395

2.395

佛既止請不欲說法，當知此法必是深妙義。今者可自推覓，何等是甚深法耶？若三乘是甚深法者，佛昔已說，不應止請。佛今既止請，當知三乘之外別有妙法，佛欲令大眾生如此心，是故止請。即是第一利益為受記因。

Since the Buddha stopped the entreaty and was unwilling to preach the Dharma, one should know that this Dharma must be of profound and marvelous meaning. Now they can search it out for themselves: what kind of Dharma is this extremely profound one? If the three vehicles were the extremely profound Dharma, the Buddha had already taught them in the past, and he should not have stopped the entreaty. Since the Buddha now stops the entreaty, one should know that apart from the three vehicles there is another marvelous Dharma. The Buddha wished to cause the great assembly to give rise to such a thought, and therefore stopped the entreaty. This is the first benefit serving as the cause for receiving prediction.