كتاب الأمور المنهي عنها
17  
The Book of the Prohibited actions
(254)
Chapter: The Prohibition of Backbiting and the Commandment of Guarding one's Tongue
(254)
باب تحريم الغيبة والأمر بحفظ اللسان
Riyad as-Salihin 1513
Sahl bin Sa'd (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "Whosoever gives me a guarantee to safeguard what is between his jaws and what is between his legs, I shall guarantee him Jannah."

[Al-Bukhari].

وعن سهل بن سعد قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏ "‏من يضمن لي ما بين لحييه، وما بين رجليه أضمن له الجنة‏"‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏
Reference : Riyad as-Salihin 1513
In-book reference : Book 17, Hadith 3