Hadith 4:741
Ubaydah ibn Humayd narrated to us, from al-Aswad ibn Qays, from Sa'id ibn 'Amr, that 'Abdullah ibn 'Umar narrated to them that the Prophet, may Allah bless him and grant him peace, said: "We are an unlettered nation; we do not write and we do not calculate. The month is like this and like this," and he struck with his hand three times, then he withheld one.
حدثنا عبيدة بن حميد عن الأسود بن قيس عن سعيد بن عمرو أن عبد الله بن عمر حدثهم أن النبي صلى الله عليه وسلم قال انا أمة أمية لا نكتب ولا نحسب الشهر هكذا وهكذا وضرب بيده ثلاثا ثم نقص واحدة