The First Duty of the Responsible Person is to Worship Allah and the Clarity of This in the Book of Allah and the Calls of the Messengers

أول واجب على المكلف عبادة الله تعالى وضوح ذلك من كتاب الله ودعوات الرسل

Awwal Wājib ʿalá al-Mukallaf ʿIbādat Allāh Taʿālā Waḍūḥ Dhālika min Kitāb Allāh wa-Daʿawāt al-Rusul