And when he began with what is most deserving of beginning, which is the declaration of disassociation from polytheism and the purification from the harm of slander, because it is from the prevention of evils, he conveyed this in a manner that is fitting for his state, blessings and peace be upon him. They were worshipping Allah, the Most High, in a manner of polytheism. The worship along with polytheism is not accepted in any way. He negated their worship of Him in the general nominal form that indicates permanence, not in the verbal form that indicates the negation of any little or much, because the verb is indefinite in the context of negation. So he said: "And you are not worshippers" meaning a worship that is accepted in such a way that it would be worthy of being a permanent description.

And when they had no dispute regarding the fact that their deity is All-Knowing, and since "what" is suitable for being applied to Him, glorified and exalted is He, he also expressed it with it because that - although there is no harm in it - is closer to fairness. It is more likely to prevent argument or disagreement. So he said: "What I worship" meaning now and afterwards, because my deity has complete knowledge and comprehensive ability - you are far removed from Him, so there is no hope for agreement between us.