維摩經略疏 4.31

4.31

If an arhat attains transcendence, he is called a mahānāga; his mind is pliable and supple, and the concrete concentrations of the three vehicles reach their ultimate here. Śāriputra roamed in these various dhyānas in the forest to rest from all toil and weariness; because he did not rely on the Buddha's wisdom to generate these various dhyānas, he was rebuked, being told "not necessary." The reason for this is that what Śāriputra attained was not the deep concentration caverns of the nine kinds of great dhyānas of the full-word teaching; hence it is said to be "not necessary."