In the third verse (82) Lut (علیہ السلام) in response to his word of advice has been put in a way that it shows that his people could not find a suitable rejoinder to what he had said. But, they were still adamant and started saying among themselves that these people seem to be self-righteous claiming a lot of purity for themselves. The treatment they deserved was that they should be thrown out of their town.
("These are indeed men who want to be pure (from sins)!") Qatadah commented, "They shamed them (Lut and the believers) with what is not a shame at all." Mujahid commented, "(Lut's people said about Lut and the believers,) They are a people who want to be pure from men's anuses and women's anuses!" Similar was narrated from Ibn `Abbas.