佛說處處經 1.23

1.23

The Buddha said to Śāriputra: "That I cause you to expound the sūtras is due to three nidānas: first, for fear that after the Buddha departs, people will not believe the words of the other bhikṣus; second, to encourage the disciples' minds and cause them to understand, [seeing that] the Buddha even has a bhikṣu expound the sūtras, how much more so other people; third, to display Śāriputra's virtues, for fear that other bhikṣus might become arrogant and wish to expound the sūtras." For these reasons, the Buddha caused Śāriputra to expound the sūtras.