The month (of Ramadan) may consist of twenty nine days, and Shu'ba (one of the narrators) (gave a practical demonstration how the Holy prophet ﷺ explained to them) by unfolding his hands thrice and folding his thumb at the third turn. 'Uqba (one of the narrators in this chain of transmitters) said: I think that he said that the month consists of thirty days and unfolded his palm three times. (Using translation from Muslim 1080m)
قَالَ رَسُولُ اللهِ ﷺ الشَّهْرُ تِسْعٌ وَعِشْرُونَ وَطَبَّقَ شُعْبَةُ يَدَيْهِ ثَلَاثَ مَرَّاتٍ وَكَسَرَ الْإِبْهَامَ فِي الثَّالِثَةِ قَالَ عُقْبَةُ وَأَحْسِبُهُ قَالَ وَالشَّهْرُ ثَلَاثُونَ وَطَبَّقَ كَفَّيْهِ ثَلَاثَ مَرَّاتٍ