Al-Baqarah 2:209

Fa-in zalaltum min baAAdi ma jaatkumualbayyinatu faAAlamoo anna Allaha AAazeezunhakeem

But if you slip [i.e., deviate] after clear proofs have come to you, then know that Allāh is Exalted in Might and Wise.

and if you slip, even after clear signs have come to you, then you must know that Allah is Mighty, Wise.