Following the rebels' defeat, he immigrated to Palestine,[4][5][6][7] where he became a Muslim waqf (religious endowment) official and grew incensed at the plight of Palestinian Arab peasants.

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.

Al-Qassam also followed the Hanafi school of fiqh (jurisprudence) of Sunni Islam and studied at the local Istambuli Mosque under the teaching of well-known ′alim (scholar) Sheikh Salim Tayarah.

[12] Following his return to Jableh, al-Qassam commenced a program of Islamic revival based on moral reforms which included the encouragement of maintaining regular salaah (prayer) and the sawm (fasting) during Ramadan as well as advocating an end to gambling and alcohol consumption.

Despite the support for Arab nationalism from some of his fellow alumni at al-Azhar and among Syrian notables, al-Qassam's loyalties at the time most likely laid with the Ottoman Empire as his relationship with the authorities would indicate.

Following Italy's September 1911 invasion of Libya, al-Qassam began collecting funds in Jableh for the joint Ottoman-Libyan resistance movement and composed a victory anthem.

A new Ottoman government in Istanbul had gained power and shifted the state's focus to the Balkan front in October, abandoning the Libyan resistance.

[15] Returning to Jableh before the war's end, al-Qassam used funds from his planned expedition to Libya to organize a local defense force to fight the French occupation.

Consequently, al-Qassam and many of his disciples left Jableh for Mount Sahyun where he established a base near the village of Zanqufeh to launch guerrilla raids against the French Army.

[16] Unlike other Muslim scholars, al-Qassam made himself easily accessible to the public and often arrived late to teach his classes because he was frequently stopped by passersby for advice.

[15] His greatest following came from the landless ex-tenant farmers drifting into Haifa from the Upper Galilee where purchases of agricultural land by the Jewish National Fund and Hebrew labour policies excluding Arabs had dispossessed many of their traditional livelihoods.

In 1929, he was appointed the marriage registrar at the sharia court in Haifa by the waqf authorities in Jerusalem,[22] a role that allowed him to tour the northern villages, whose inhabitants he encouraged to set up agricultural cooperatives.

According to the American historian Edmund Burke, al-Qassam wasAn individual deeply imbued with the Islamic social gospel and who was struck by the plight of Palestinian peasants and migrants.

Al-Qassam's pastoral concern was linked to his moral outrage as a Muslim at the ways in which the old implicit social compact was being violated in the circumstances of British mandatory Palestine.

[23]He also took advantage of his travels to deliver fiery political and religious sermons in which he encouraged villagers to organise resistance units to attack the British and Jews.

[15] He intensified his agitation and obtained a fatwa from Shaykh Badr al-Din al-Taji al-Hasani, the Mufti of Damascus, which ruled that the struggle against the British and the Jews was permissible.

[27] In particular, he developed a strong relationship with leading local party member Rashid al-Hajj Ibrahim, the previous president of the Haifa YMMA.

A wide ideological gap between the secularist al-Istiqlal and al-Qassam was bridged by a convergence in the view that the struggle against Zionist expansion in Palestine was inseparable from active opposition to British rule.

The moral component of al-Qassam's teachings were especially geared towards the young men of Haifa's labour slums who lived away from their families and who were exposed to activities considered immoral in Islam.

[31] He viewed marriage as key to preventing the moral corruption of young men and managed to financially aid his more destitute supporters with their wedding expenses.

[35] Following the October 1935 discovery of a clandestine cache of arms in the port of Jaffa apparently originating from Belgium and destined for the Haganah, a Jewish paramilitary force,[36] Palestinian Arab indignation broke out in two general strikes.

[15][38] The manner of his last stand galvanized Palestinians at the time, according to American historian Abdallah Schleifer:[9] Surrounded, he told his men to die as martyrs, and opened fire.

Thousands forced their way past police lines at the funeral in Haifa, and the secular Arab nationalist parties invoked his memory as the symbol of resistance.

[9]To the surprise of the Palestine Police Force, al-Qassam's funeral, which was held at the Jerini Mosque, attracted at least 3,000 mourners, mostly members of the peasant and working classes.

[41] An obituary for al-Qassam was published in the Egyptian newspaper Al-Ahram on 22 November, eulogizing him as a "martyr" with the following statement: "I heard you preaching from up in the pulpit, summoning to the sword ...

[9] At the start of the revolt, al-Qassam's close disciples al-Sa'di, Abu Ibrahim al-Kabir, and Attiyah Ahmad Awad led fasa'il in the Jenin region, the Upper Galilee and Balad al-Sheikh, respectively.

"[47] In his speech from Bint Jbeil celebrating the Israeli withdrawal from South Lebanon on 24 May 2000, Hezbollah leader Hassan Nasrallah addressed the Palestinians saying: Our people in Palestine, your destiny lies within your reach, and you can retain your land with your will, with Ezzeddine Al-Qassam's choice, and with the blood of Fathi Shaqaqi and Yahya Ayyash.