Ghafir: 66
"Say: I have been forbidden..."
If you ask: Was the Messenger of Allah (ﷺ) not forbidden from the worship of idols by the proofs of reason before the clear signs (al-bayyinat) came to him from his Lord?
I say: Yes, he was. However, because the clear signs served to strengthen the proofs of reason, confirm them, and incorporate their mention—such as the Almighty’s saying: "Do you worship what you carve? While Allah created you and what you make" (al-Saffat: 95-96), and similar instances that alert one to the proofs of reason—the mention of the clear signs was a mention of both the proofs of reason and revelation (al-sam') together.
He only mentioned that which points to both matters because the mention of the mutual support between the proofs of reason and the proofs of revelation is more powerful in invalidating their doctrine, even if the proofs of reason alone were sufficient.
"It is He who created you from dust, then from a drop of fluid, then from a clinging clot, then He brings you out as a child, then [He lets you reach] your maturity, then [He lets you reach] old age—though some of you die before—and [He lets you reach] a specified term, so that you may use your reason."