This study examines the relationship between the purpose of marriage in Minangkabau custom and the Qur'anic teaching of Q.S. ar-Rum 21, as read through Tafsir al-Azhar by Buya Hamka and Tafsir Qur'an Karim by Mahmud Yunus. It responds to the gap between the Qur'anic ideal of marriage as a path toward sakinah, mawaddah, and rahmah and the persistence of rising divorce rates, which suggest that this ideal is not always realized in practice. Using a library-based comparative (muqarin) method, the study treats the two commentaries as primary data and literature on Minangkabau marriage custom as secondary data, analyzed descriptively-analytically and read through Roibin's theory of religion-culture relations. The results show, first, that Minangkabau marriage purposes arise from three interrelated drives: fulfilling custom itself, religious injunction, and marriage's status as a social event binding extended kin groups rather than merely two individuals. Second, Hamka and Mahmud Yunus concur that Q.S. ar-Rum 21 affirms the creation of a spouse as a sign of God's greatness intended to cultivate tranquillity, love, and compassion, differing chiefly in interpretive depth: Hamka elaborates the verse through the five maqashid al-shari'ah and the changing character of love with age, while Mahmud Yunus renders it concisely and literally. Third, the relation between the two is compromistic rather than confrontational, culminating in a pattern of acculturation in which Qur'anic values supply the normative grounding while Minangkabau custom furnishes its concrete social expression.