Abdul Hamid, Hamizul bin, Ahmad Faisal Abdul Hamid, and Adibah Abdul Wahab. 2019. “Development of Zakat Collection During Caliph Umar Al-Khattab”. Journal Al-Muqaddimah 6 (1):28-42. https://jml.um.edu.my/index.php/MUQADDIMAH/article/view/15708.