The Prophet ﷺ said, "A servant may speak a word that pleases Allah, giving it no thought, by which Allah raises him in rank. And a servant may speak a word that angers Allah, giving it no thought, by which he plunges into Hell."
عن النبي ﷺ، قال: إن العبد ليتكلم بالكلمة من رضوان الله، لا يلقي لها بالا، يرفع الله بها درجات، وإن الله العبد ليتكلم بالكلمة من سخط الله، لا يلقي لها بالا، يهوي بها في جهنم.
Bukhari narrated it in the chapter on Riqaq (6478), from Abdullah bin Munir, who heard Abu Nadr, who said, Abdul-Rahman bin Abdullah - meaning Ibn Dinar - told us, from his father, from Abu Salih, from Abu Hurairah, and he mentioned it.