أَلَمْ نُهْلِكِ الْأَوَّلِينَ (Did We not destroy the earlier people?...77:16) It refers to the nations of ` Ad, Thamud, nation of Lut (علیہ السلام) and Fir'aun (The Pharaoh) who were destroyed because of their obstinacy.
He has revealed to you ˹O Prophet˺ the Book in truth, confirming what came before it, as He revealed the Torah and the Gospel