[Among the requirements of this testimony is to devote every kind of worship exclusively to Allah]
Realizing tawḥīd (monotheism) entails acknowledging that Allah, exalted is He, has established for Himself a right in which no creature may share—such as worship, reliance, fear, reverential awe, and piety. The Almighty says: “Do not set up another god alongside Allah, lest you sit disgraced and forsaken” (17:22). He also says: “Indeed, We have sent down to you the Book in truth; so worship Allah, devoting the religion sincerely to Him. Truly, sincere devotion belongs to Allah alone” (39:2–3). And He says: “Say, ‘I have been commanded to worship Allah, devoting the religion sincerely to Him’” (39:11). He further says: “Say, ‘Is it other than Allah that you command me to worship, you ignorant ones? It has already been revealed to you and to those before you that if you associate partners with Allah, your deeds will certainly come to nothing and you will assuredly be among the losers. Rather, worship Allah and be among the grateful’” (39:64–66). Every messenger who was sent would say to his people: “Worship Allah; you have no deity other than Him.”