法華義疏 3.128

3.128

身子根緣先熟最初領悟，又是逐佛轉法輪大將。又今說平等第一智慧，宜對智慧之人。又根緣所宜故也。

Śāriputra's faculties and conditions were the first to ripen, and he was the first to comprehend; furthermore, he was the great general who followed the Buddha in turning the wheel of the Dharma. Moreover, now preaching the peerless, foremost wisdom, it is fitting to address a person of wisdom. In addition, it was what his faculties and conditions called for.