Mu'in was born to the large landowning Palestinian Arab family, al-Madi, in the town of Ijzim west of the Jezreel Valley.

Al-Madi's demotion and trial left him embittered with the Ottoman authorities and after his release, he took up an alias and hid in the house of an Arab Christian, Najib al-Hakim, in Damascus.

[3] From 1918, al-Madi was among the focal members of an emerging group of Arab nationalists based in Haifa and linked to the pan-Arab movement of Syria which also included Rashid al-Haj Ibrahim, a prominent businessman and local Haifan leader.

Initially, al-Madi's activities centered on the Hashemites, who led the Arab Revolt against the Ottoman Turks in 1917.

[6] He and Najib al-Hakim joined and offered their services without charge to the Haifa branch of the Palestine Arab Workers Society (PAWS) upon its founding in 1925, in order to counter the influence of the Jewish labor organization, Histadrut.

[8] He was later appointed to the Arab Higher Committee (AHC), established in early 1936 by the Grand Mufti of Jerusalem, Mohammad Amin al-Husayni.

He was again sent to Iraq (with Izzat Darwaza and al-Haj Ibrahim) in January 1937, as well as to Riyadh, to garner support for the Arab revolt in Palestine that was initiated the year prior.