What do Ibn al-Shatir and Ibn Tufail have in common?
Ibn al-Shatir Ibn al-Shatir or Ibn ash-Shatir (Arabic: ابن الشاطر‎ ‎ ; 1304–1375) was an Arab astronomer. He worked as "muwaqqit" (موقت, religious timekeeper) in the Umayyad Mosque in Damascus and constructed a sundial for its minaret in 1371/72.
Abu al-Fadl Ja'far ibn 'Ali al-Dimashqi Abū al-Faḍl Jaʻfar ibn ʻAlī al-Dimashqī (Arabic: أبو الفضل جعفر بن علي الدمشقي‎ ‎ ; fl. 12th-century) was a prosperous Muslim merchant from Damascus. He is best known for being the author of "Kitab al-Isharah ila Mahasin at-Tijarah wa Marifat Jayyid al-A’rad wa Kadiiha wa Ghush-ush al-Mudallisin fiha" (A Guide to the Merits of Commerce and to Recognition of Both Fine and Defective Merchandise and the Swindles of Those Who Deal Dishonestly).