法華玄論 2.133

2.133

十六者佛初成正覺，故蓮華藏世界說一乘法門；今為二乘人說於一乘，令二乘人同入法界共在蓮華藏土，故借蓮華以表此義。

Sixteenth, when the Buddha first attained correct enlightenment, he preached the Dharma gate of the one vehicle in the Lotus Treasury World; now, preaching the one vehicle for the sake of those of the two vehicles, he enables those of the two vehicles to enter the dharmadhātu together and dwell together in the Lotus Treasury Realm; therefore the lotus flower is borrowed to represent this meaning.