Hekayat 84 from Chapter 8 of Golestan of Saadi

I had a sore on my body and the Sheikh would ask every day how it was, but he never asked where it was. I understood that he avoided mentioning it because it is inappropriate to speak of every part of the body. Wise men have said that those who do not weigh their words carefully will be offended by the response.

Until you are sure that your words are truly correct,

You should not open your mouth to speak.

If you speak the truth and are imprisoned,

It is better than being freed by a lie.

ریشی درون جامه داشتم و شیخ از آن هر روز بپرسیدی که چون است و نپرسیدی کجاست. دانستم از آن احتراز می‌کند که ذکر همه عضوی روا نباشد و خردمندان گفته‌اند هر که سخن نسنجد، از جوابش برنجد.

تا نیک ندانی که سخن عین صواب است

باید که به گفتن دهن از هم نگشایی

گر راست سخن گویی و در بند بمانی

به زآن که دروغت دهد از بند رهایی