Jami at-Tirmidhi 690
Jami at-Tirmidhi · Book 8: The Book on Fasting · What Has Been Related About: The Month Is Twenty-Nine Days
Anas narrated:
حَدَّثَنَا عَلِيُّ بْنُ حُجْرٍ ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ ، عَنْ حُمَيْدٍ ، عَنْ أَنَسٍ ، أَنَّهُ قَالَ آلَى رَسُولُ اللَّهِ صلى الله عليه وسلم مِنْ نِسَائِهِ شَهْرًا فَأَقَامَ فِي مَشْرُبَةٍ تِسْعًا وَعِشْرِينَ يَوْمًا قَالُوا يَا رَسُولَ اللَّهِ إِنَّكَ آلَيْتَ شَهْرًا فَقَالَ " الشَّهْرُ تِسْعٌ وَعِشْرُونَ " . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
"The Messenger of Allah vowed to stay away from his wives for a month, so he stayed in a loft for twenty-nine days. They said: 'O Messenger of Allah, your vow was for a month,' so he said: 'The month is twenty-nine (days).'"
Grade: Sahih (Darussalam)