جامع الترمذي

Ibn Mas`ud said: "What I fasted with the Prophet (ﷺ) that was twenty-nine (days), was more than what we fasted that was thirty." (He said): There are narrations on this topic from `Umar, Abu Hurairah, `A'isha, Sa`d bin Abi Waqqas, Ibn `Abbas, Ibn `Umar, Anas, Jabir, Umm Salamah, Abu Bakrah, that the Prophet (ﷺ) said: "The month is twenty nine (days)."