The sociology of religion has often missed the mark with Islam and Muslims, by forcing external frameworks that are not fit for purpose, by neglecting already-existing constitutive theories that more authentically explain the Muslim experience, and by devoting comparatively fewer studies to Islam and Muslims. This paper offers a small contribution to redress these issues, by examining the religious lives of everyday Melbourne Muslims in Ramadan, using theories first proposed by Ibn Khaldun. By extending Ibn Khaldun's concept of 'asabiyya (social binding), this paper explores for the first time the interdependent roles of hardship and Islam in generating a nourishing sense of community cohesion. The research was conducted through anonymous diaries kept over an extended period, providing unprecedented and novel insights into the lives of participants. The findings suggest that the physical and spiritual challenges of Ramadan, combined with the influence of "transnational" Islam, contribute to the formation of 'asabiyya. Sociological instruments used to understand Muslims are too often external and not fit-for-purpose. This paper expands theories first proposed by Ibn Khaldun 600 years ago, particularly 'asabiyya, and then applies them in new ways to better explain the modern Muslim experience in Ramadan.