法華論疏 3.240

3.240

以初發菩提心，次令修菩薩行。菩薩行比四乘行最為無上，故言行無上也。

Because after initially generating the bodhicitta, one is next caused to cultivate bodhisattva practice. Bodhisattva practice is the most peerless compared to the practice of the four vehicles; therefore, it is called peerless practice.