Sirach 32:7-9

Revised Standard Version Catholic Edition

⁷ Speak, young man, if there is need of you,
    but no more than twice, and only if asked.
⁸ Speak concisely, say much in few words;
    be as one who knows and yet holds his tongue.
⁹ Among the great do not act as their equal;
    and when another is speaking, do not babble.