How did Arabic coinage strengthen Umayyad rule?

The introduction of Arabic coinage was a central component of the Umayyad dynasty's broader program of Arabization, initiated by the caliph ‘Abd al-Malik in the late 7th century to centralize authority and solidify the Islamic identity of the state.12

Prior to this reform, the Umayyads had relied on imitations of Byzantine and Sasanian coins, which often featured non-Muslim imagery. By replacing these with a distinctively Islamic currency—consisting of gold dinars and silver dirhams—the caliphate achieved several strategic goals:32

• Religious Legitimacy: The new coins removed pictorial types and replaced them with skillfully arranged Arabic inscriptions, including the Muslim profession of faith and verses from the Qur’ān, effectively asserting the supremacy of Islam.3
• Administrative Standardization: The reform was part of a wider effort to make Arabic the official language of administration, replacing Persian and Greek officials with an Arabized class of administrators.12
• Economic Sovereignty: By establishing their own currency standards, the Umayyads reduced reliance on foreign monetary systems, reinforcing the empire's political and economic independence.32