Riyad as-Salihin
Riyad as-Salihin 1513
The Prohibition of Backbiting and the Commandment of Guarding one's Tongue
Arabic hadith text
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)).
Translation
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].