You are reading a tafsir for the group of verses 21:74 to 21:75
وَلُوْطًا
اٰتَیْنٰهُ
حُكْمًا
وَّعِلْمًا
وَّنَجَّیْنٰهُ
مِنَ
الْقَرْیَةِ
الَّتِیْ
كَانَتْ
تَّعْمَلُ
الْخَبٰٓىِٕثَ ؕ
اِنَّهُمْ
كَانُوْا
قَوْمَ
سَوْءٍ
فٰسِقِیْنَ
۟ۙ
وَاَدْخَلْنٰهُ
فِیْ
رَحْمَتِنَا ؕ
اِنَّهٗ
مِنَ
الصّٰلِحِیْنَ
۟۠
3

Commentary

The name of the city from which Sayyidna Lut (علیہ السلام) was saved and which has been mentioned in these verses was Sodom. There were seven other townships under this city which were thrown upside down by Jibra'il (علیہ السلام) except one which was left intact for Lut (علیہ السلام) and his followers. (Ibn ` Abbas, Qurtubl)

تَّعْمَلُ الْخَبَائِثَ (21:74) خَبَائِثَ (Khaba'ith) is the plural of خَبِئیثَہ meaning wickedness. Too many wicked things collectively are called Khaba'ith (خَبَائِثَ ). Their most abominable practice in which even the animals do not indulge, was sodomy or homosexuality. It is possible that because of its extreme wicked nature this practice is referred to as خَبَائِثَ that is in plural instead of خَبِئیثَہ in singular, as some commentators have explained. The second explanation is that the people of Sodom also indulged in other bad habits such as drinking, singing, shaving off beard, growing moustaches, wearing silk clothes, stone throwing, whistling etc. (Ruh ul-Ma` ani).