MUSLIM 1080n: from Ibn ʿUmar Yuḥaddith —
We are an unlettered people who can neither write nor count. The month is thus, and thus. folding his thumb when he said it the third time.

مسلم ١٠٨٠n: عن ابن عمر يحدث —
عَنِ النَّبِيِّ ﷺ قَالَ إِنَّا أُمَّةٌ أُمِّيَّةٌ لاَ نَكْتُبُ وَلاَ نَحْسُبُ الشَّهْرُ هَكَذَا وَهَكَذَا وَهَكَذَا وَعَقَدَ الإِبْهَامَ فِي الثَّالِثَةِ وَالشَّهْرُ هَكَذَا وَهَكَذَا وَهَكَذَا يَعْنِي تَمَامَ ثَلاَثِينَ


Sound (Muslim)
Muslim > Ṣawm (Fasting) > § The obligation to fast Ramadan when the crescent is...
hadithunlocked.com