Translation of the verse 13 from Surah Fussilat : Number of verses 54 - - page 478 - Part 24.
But if they turn away, then say (O Muhammad SAW): "I have warned you of a Sa'iqah (a destructive awful cry, torment, hit, a thunderbolt) like the Sa'iqah which overtook 'Ad and Thamud (people)."
But if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] 'Aad and Thamud.
(41:13) But if they turn away, *17 tell them: 'I warn you against a sudden scourge like that which struck Ad and Thamud.'
*17) That is, "Ifthey do not believe that God and Deity is One and only One, who has created this earth and the whole universe, and still persist in their ignorance that they would make others also, who are in fact His creatures and slaves, deities beside Him, and regard them as His associates in His Being and rights and powers.