It was narrated from Muhammad bin Sa’d bin Abu Waqqas that his father said:
“The Messenger of Allah ﷺ said: ‘The month is like that and like that and like that,’ and he showed nine fingers on the third time to indicate twenty-nine.”

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ، عَنْ إِسْمَاعِيلَ بْنِ أَبِي خَالِدٍ، عَنْ مُحَمَّدِ بْنِ سَعْدِ بْنِ أَبِي وَقَّاصٍ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ ﷺ ـ " الشَّهْرُ هَكَذَا وَهَكَذَا وَهَكَذَا " . وَعَقَدَ تِسْعًا وَعِشْرِينَ فِي الثَّالِثَةِ .