Here Allah tells us about His servant and Messenger Hud, when he called his people `Ad. His people used to live in the Ahqaf, curved sand-hills near Hadramawt, on the borders of Yemen. They lived after the time of Nuh, as Allah says in Surat Al-A`raf:
(And remember that He made you successors after the people of Nuh and increased you amply in stature) (7:69). This refers to the fact that they were physically strong and well-built, and very violent, and very tall; they had also been given a great deal of provisions, wealth, gardens, rivers, sons, crops and fruits. Yet despite all of that, they worshipped others besides Allah. So Allah sent Hud, one of their own, as a Messenger bringing them good news and delivering warnings. He called them to worship Allah alone, and he warned them of Allah's wrath and punishment if they were to go against him and treating him harshly. He said to them, as Nuh had said to his people:
They said, "Shall we believe in you while you are followed by the lowest people?" [ 111] He said, "I do not know about what they do. (26:111-112)
It is related in this verse that the disbelievers rejected the invitation of Sayyidna Nuh (علیہ السلام) to accept the faith on the plea that his followers were worthless poor people. So, how could they, the elite and noble, mix up with them? On this Nuh (علیہ السلام) replied that he did not know about their acts, thereby hinting that their understanding of nobility on the basis of family background, wealth, or status was wrong, and that the nobility or meanness and honour or disgrace is dependent on one's deeds and morals. Hence, it was their ignorance to put the label of sordidness on his followers, because they did not know about their deeds and disposition. Unless one knows fully well about the morals and deeds of others, it is not right to pass any judgment about them. (Qurtubi).
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 122–134
Noah strove for centuries so that his community could realize the truth, but they refused to accept it. The moral debasement of his people had reached its acme and the disbelievers now threatened Noah either to stop preaching or be stoned to death. Noah then prayed to God to judge decisively between him and the disbelievers. His prayer was answered. At God’s behest, Noah constructed a large boat, in which all his companions and the male and female counterparts of each animal species were accommodated. Thereafter, God sent a severe storm; water gushed out of the earth, and there was a heavy downpour of rain from the skies. All the living creatures, except those on the boat, were destroyed. This historical example is an embodiment of the fact that while true believers would remain protected, all others would face destruction.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.