In Islamic culture, "Hilm" (forbearance) is a concept closely related to emotion regulation, particularly anger management. This study focuses on the development of a "Hilm" questionnaire within the domain of anger, employing both qualitative and quantitative approaches. In the qualitative phase, using the "conventional qualitative content analysis" method, a conceptual model of "Hilm" was derived from Islamic sources, with an emphasis on anger control. Based on the findings of the qualitative study, a 60-item questionnaire was developed and administered to a sample of 824 participants recruited from the social media platforms "Eitaa", "WhatsApp", and "Telegram". Through"exploratory factor analysis (EFA)", four main factors—"Cognitive Management, Forgiveness, Anger, and Thought Rigidity"—were identified. Additionally, three sub-factors emerged for the first factor: "Conscious Control, Non-engagement, and Empathy". Content validity was assessed using the "Content Validity Index (CVI)". To evaluate criterion validity, a measure of "aggression" was simultaneously administered to a subset of 176 participants, confirming the expected relationships. Convergent and divergent validity evidence was provided and deemed satisfactory. The internal consistency of the questionnaire was confirmed with a "Cronbach’s alpha coefficient of 0.959". Reliability at the factor and sub-factor levels was also assessed and validated.