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.
Tatbir Tatbir (Arabic: تطبير‎ ‎ ), also known as Talwar zani and Qama Zani in South Asia, is an act of mourning by some of Shia Muslims for the younger grandson of Muhammad, Husayn ibn Ali, who was killed along with his children, companions and near relatives at the Battle of Karbala by the Umayyad Caliph Yazid I. Tatbir is a contested issue among Shia. Most clerics deem it to be self-damage and hence Haram. However, a small minority of Shia do perpetuate the practice in defiance.