وَقَوْمَ نُوحٍ مِّن قَبْلُ ۖ إِنَّهُمْ كَانُوا هُمْ أَظْلَمَ وَأَطْغَىٰ
“And the people of Noah before. Indeed, it was they who were [even] more unjust and oppressing.”
This ayah is part of Surah al-Najm, which the Prophet ﷺ recited in full at this event -- building to the prostration verse (53:62) that moved even the Quraysh to fall into sajdah with the Muslims.