(To keep one’s self pure) means to rise above impurity and foulness. For example, when a group of young men gamble and commit immoralities, then someone comes up to them and tells them that what they are doing is unlawful (haram), it is not permissible and it does not coincide with morals, so they push him away from them saying that he is not one of them and accuse him of being a person who keeps himself pure. This was how the people of Prophet Lot (PBUH) answered him (PBUH), that he should be exiled out of the village along with anyone who believed in his calling (PBUH) and denied this abomination. We note here that Allah (swt) does not talk about worshiping and fearing Him (swt) as was the case with previous Prophets (PBUT). In this verse, Allah (swt) wants to focus the attention on the heinous immorality committed by the people of Prophet Lot (PBUH). The discussion between Prophet Lot (PBUH) and his people revolved around one topic, which was about that immoral act.