The Book of Fasting
13/4. Chapter:
The month may be twenty-nine days
Sahih Muslim
حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَخْبَرَنَا اللَّيْثُ، ح وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، - وَاللَّفْظُ لَهُ - حَدَّثَنَا لَيْثٌ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، - رضى الله عنه - أَنَّهُ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم اعْتَزَلَ نِسَاءَهُ شَهْرًا فَخَرَجَ إِلَيْنَا فِي تِسْعٍ وَعِشْرِينَ فَقُلْنَا إِنَّمَا الْيَوْمُ تِسْعٌ وَعِشْرُونَ . فَقَالَ " إِنَّمَا الشَّهْرُ " . وَصَفَّقَ بِيَدَيْهِ ثَلاَثَ مَرَّاتٍ وَحَبَسَ إِصْبَعًا وَاحِدَةً فِي الآخِرَةِ .
Jabir (Allah be pleased with her) narrated that the Prophet (ﷺ) separated himself from his wives for a month. (His wives said: ) He came to us on the twenty-ninth day, whereupon we said: It is the twenty-ninth (day) today. Thereupon he said: So far as the month is concerned, (and he, with a view to explaining it) flapped his hands thrice, but held back one finger at the last turn.
Reference : Sahih Muslim 1084aIn-book reference : Book 13, Hadith 27USC-MSA web (English) reference : Book 6, Hadith 2385