法華義疏 7.42

7.42

蓋是互現不同，又示身子利根能推理同教異，故昔憂今喜；中根之人但保執小教謂為至極，故昔不懷憂也。

This is merely a mutual demonstration of difference. Furthermore, it shows that Śāriputra, having sharp capacity, was able to deduce that while the principle is the same, the teachings differed, and hence he grieved in the past and rejoiced in the present; whereas those of medium capacity merely clung to and upheld the Hīnayāna teaching, considering it the ultimate, and therefore did not harbor grief in the past.