Hekayat 13 from Chapter 7 of Golestan of Saadi

A Hindu man was learning the skill of fire-juggling with oil. A wise man remarked to him, “For someone whose home is made of reeds, this is not a game to play.”

Do not speak until you know your words are truly right,
And say nothing if you know it won’t bring good insight.

هندوی نفط‌ اندازی همی‌آموخت. حکیمی گفت تو را که خانه نیین است، بازی نه این است.

تا ندانی که سخن عین صواب است مگوی

وآنچه دانی که نه نیکوش جواب است مگوی