In the case of words that the Tathagata
knows to be factual, true, beneficial,
and endearing and agreeable to others,
he has a sense of the proper time for saying them.
– Sakyamuni Buddha
Of all the Buddha’s disciples, Sariputta [or Sariputra] was best able to understand and explain the Dharma, and in this way he was only second to the Buddha himself. Once the Buddha said to him: “You are wise, Sariputta, great and wide is your wisdom, joyful and quick is your wisdom, sharp and analytical is your wisdom. Just as the eldest son of a Universal Monarch rules rightly as his father did, even so do you turn the wheel of the Dharma just as I have.” (S,I:191)
Such regard did the Buddha have for Sariputta that he gave him the title General of the Dharma (Dharmasenapati). In one of his discourses, Sariputta talked about the qualities needed to teach the Dharma and we can safely assume that he emphasised these same qualities when he was teaching. “When one who teaches wishes to teach another, let him establish well five things and then teach. What five? Let him think:
 ‘I will speak at the right time, not at the wrong time.
 I will speak about what is, not about what is not.
 I will speak with gentleness, not with harshness.
 I will speak about the goal, not about what is not the goal.
 I will speak with a mind filled with love, not with a mind filled with ill-will.’
When one who teaches wishes to teach another, let him establish well these five things.” (A,III:195)
The Buddha and His Disciples
Ven. S. Dhammika