What do Al-Nayrizi and Avicenna have in common?
Al-Nayrizi Abū’l-‘Abbās al-Faḍl ibn Ḥātim al-Nairīzī (Arabic: أبو العباس الفضل بن حاتم النيريزي‎ ‎ , Latin: "Anaritius, Nazirius" , 865–922) was a Persian mathematician and astronomer from Nayriz, Fars Province, Iran.
Ishaq Ibn Rahwayh Abū Yaʻqūb Isḥāq ibn Ibrāhīm ibn Mukhallad al-Ḥanzalī (Arabic: أبو يعقوب إسحاق بن إبراهيم بن مخْلد الحنظلي‎ ‎ ), commonly known as Ishaq Ibn Rahwayh (Arabic: إسحاق بن راهويه‎ ‎ ; 161 AH – 238 AH), was the muhaddith, faqih and the imam of Khurasan of his time. He was given the title of "the leader of the believers in the field of hadith" (amir al-muʼminīn fī al-ḥadīth) for his major contributions to the science of hadith. It is said that Ibn Rahwayh memorized more than one hundred thousand hadiths.