The Messenger Establishes Pure Monotheism
The Prophet ﷺ devoted himself to instilling this monotheism in his community and to cutting off every conduit that might lead to associating partners with Allah. This is the true fulfilment of our declaration, “There is no god but Allah,” for the ilāh is the One whom hearts worship out of perfect love, veneration, reverence, honor, hope, and fear.
Thus he instructed them, “Do not say, ‘Whatever Allah and Muhammad will,’ but say instead, ‘Whatever Allah wills, then whatever Muhammad wills.’” On another occasion a man told him, “Whatever Allah and you will,” whereupon he replied, “Have you made me a rival to Allah? Rather, say, ‘Whatever Allah alone wills.’”
He also said, “Whoever must swear an oath, let him swear by Allah, or else remain silent,” and, “Whoever swears by anything other than Allah has committed shirk.”
To Ibn ʿAbbās he counselled, “When you ask, ask Allah; and when you seek help, seek help from Allah. The Pen has dried concerning everything you will face: were all creation to strive to benefit you, they would never benefit you except with what Allah has already written for you; and were they to strive to harm you, they would never harm you except with what Allah has already written against you!”