The Apostle of Allah ﷺ separated himself from his wives for a month. (His wives said: ) He came to us on the morning of the twenty-ninth. Upon this some, of the people said: It is the morning of twenty- ninth (according to our calculation). Upon this the Messenger of Allah ﷺ said: The month. may also consist of twenty-nine days. The Apostle of Allah ﷺ then flapped his bands thrice, twice with all the fingers of both his hand (to indicate twenty-nine) and by the third time with nine (fingers). (Using translation from Muslim 1084b)
أَنَّهُ سَمِعَ جَابِرًا يَقُولُ اعْتَزَلَ رَسُولُ اللهِ ﷺ نِسَاءَهُ شَهْرًا فَخَرَجَ صَبَاحَ تِسْعَةٍ وَعِشْرِينَ فَقَالَ النَّبِيُّ ﷺ «إِنَّ الشَّهْرَ يَكُونُ تِسْعَةً وَعِشْرِينَ» ثُمَّ صَفَّقَ نَبِيُّ اللهِ ﷺ بِيَدَيْهِ ثَلَاثًا مَرَّتَيْنِ بِأَصَابِعِ يَدَيْهِ كُلِّهَا وَالثَّالِثَةَ بِالتِّسْعِ مِنْهَا