The Messenger of Allah ﷺ said, "Shall I tell you of the gravest of major sins?"They replied, "Yes, Messenger of Allah."He said, "Associating partners with Allah and disobedience to one's parents."He had been reclining, but then he sat up and said, "And false testimony," or "false speech."The Messenger of Allah ﷺ kept repeating it until we wished he would stop.
حدثنا حميد بن مسعدة حدثنا بشر بن المفضل حدثنا الجريري
قال رسول الله ﷺ ألا أحدثكم بأكبر الكبائر قالوا بلى يا رسول الله قال الإشراك بالله وعقوق الوالدين قال وجلس وكان متكئا فقال وشهادة الزور أو قول الزور فما زال رسول الله ﷺ يقولها حتى قلنا ليته سكت
Agreed upon [by Bukhari and Muslim]. Bukhari narrated it in "Testimonies," chapter on what has been said regarding false testimony, hadith no. 2654, from the hadith of Bishr bin Mufaddal, and Muslim narrated it, hadith no. 87, from the hadith of Jareeri, through the same chain.There is also a narration on this subject from Abu Saeed [Abu Dawud, hadith no. 2530].