(Say: I am (relying) on clear proof from my Lord…) [6:57].
Said al-Kalbi: “This verse was revealed about al-Nadr ibn al-Harith and the chiefs of Quraysh. They used to say mockingly to the Prophet: ‘O Muhammad bring on us the chastisement you promised us’, and so this verse was revealed”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou