法華義疏 3.220

3.220

唯佛獨有善巧。十地已下雖有化物之能，未窮善巧之極，餘人所無故稱第一。又佛乘為第一，昔說三乘為令悟一，則與第一為方便，故名第一也。

Only the Buddha alone possesses this skillfulness. Those from the ten stages on down, although having the ability to transform beings, have not exhausted the utmost limit of skillfulness; since other people lack it, it is called foremost. Furthermore, the Buddha vehicle is foremost; formerly expounding the triyāna was to cause awakening to the one, so it serves as the expedient means for the foremost, and is therefore called foremost.