 Al-Qassam was born in Jableh, northwestern Syria, to father Abd al-Qadar, a Sharia court official during Ottoman rule and a local leader of the Qadariyya Sufi order. His grandfather had been a leading sheikh of the Qadariyya order and moved to Jableh from Iraq. Al-Qassam also followed the Hanafi fiqh (school of jurisprudence) of Sunni Islam and studied at the local Istambuli Mosque under the teaching of well-known ′ alim (scholar) Sheikh Salim Tayarah.
