Kaplan, Muhammed Nur, and Arif Afandi Zarkasyi. “Purification of Sufism According to Hamka”. Kalimah: Jurnal Studi Agama dan Pemikiran Islam 22, no. 2 (September 30, 2024): 141–166. Accessed December 5, 2025. https://ejournal.unida.gontor.ac.id/index.php/kalimah/article/view/12909.