حَدَّثَنَا عَبْدُ الرَّحْمَنِ عَنْ سُفْيَانَ وَإِسْحَاقُ يَعْنِي الْأَزْرَقَ قَالَ حَدَّثَنَا سُفْيَانُ عَنِ الْأَسْوَدِ بْنِ قَيْسٍ عَنْ سَعِيدِ بْنِ عَمْرٍو عَنِ ابْنِ عُمَرَ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِنَّا أُمَّةٌ أُمِّيَّةٌ لَا نَكْتُبُ وَلَا نَحْسُبُ الشَّهْرُ هَكَذَا وَهَكَذَا حَتَّى ذَكَرَ تِسْعًا وَعِشْرِينَ قَالَ إِسْحَاقُ وَطَبَّقَ يَدَيْهِ ثَلَاثَ مَرَّاتٍ وَحَبَسَ إِبْهَامَهُ فِي الثَّالِثَةِ
مسند امام احمد بن حنبل · Hadith 5137
It was narrated from Ifcn 'Umar that the Prophet (PBUH) said "We are an unlettered ummah, we do not write or calculate. The month is like this and like this and like this," so as to indicate twenty-nine. Ishaaq said: and he dapped his hands three times and tucked away his thumb the third time.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020