(4) باب الشَّهْرِ يَكُونُ تِسْعًا وَعِشْرِينَ
Narrated Abdullah ibn Mas'ud:
We kept fast for twenty-nine days along with the Prophet (ﷺ) more often than we kept fast for thirty days. (ES)
Reference (ES): Sunan Abi Dawud 2322 (ES)
In-book reference (ES): Book 14, Hadith 10 (ES)
English translation (ES): Book 13, Hadith 2315 (ES)