Why is «إِنَّهُمْ مُغْرَقُونَ» reinforced?

Departing from the Expected Form: Rhetorical Reclassification of the Addressee

• Nūḥ explicitly denied the drowning
• The preceding clue treats a non-questioner as an expectant questioner
• The word mughraqūn is meaningless
• Every Qur’anic report must use inna