﴿ فَإِنْ أَعْرَضُوا۟ فَقُلْ أَنذَرْتُكُمْ صَٰعِقَةًۭ مِّثْلَ صَٰعِقَةِ عَادٍۢ وَثَمُودَ ﴾

“BUT IF they turn away, say: “I warn you of [the coming of] a thunderbolt of punishment like the thunderbolt [that fell upon the tribes] of Ad and Thamud!””

(But if they) the disbelievers of Mecca: 'Utbah and his host (turn away) from faith, (then say: I warn you) by means of the Qur'an (of a thunderbolt) of a punishment (like the thunderbolt) like the punishment ((which fell of old upon the tribes) of 'Aad and Thamud;