Walaqad tarakna minha ayatan bayyinatan liqawmin yaAAqiloon (surah Ankabut: 35)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(29:35) And We have left a vestige of it in that city as a Clear Sign *57 *59 for a people who use their reason. *60

Wa laqat taraknaa min haaa aayatam baiyinatal liqawminy ya`qiloon

*57) The reason for this anxiety and distress was that the angels had come in the shape of handsome, young boys. The Prophet Lot was aware of his people's morals. Therefore, he became perturbed at their arrival. He was thinking, "If I receive these guests in my house, it will be difficult to save them from the immoral people; if I do not receive them, it will be highly uncivil and unbecoming of the noble people. Moreover, if I do not provide shelter to these travelers, they will stay the night elsewhere, which would mean that I have myself given them away to the wicked people." What happened after this has not been related here. But according to the details given in Surahs Hud, AI-Hijr and AI-Qamar, the people of the city thronged to the Prophet Lot's house and insisted that the guests be handed over to them for immorality.
*59) "A clear Sign": the Dead Sea, which is also called Sea of Lot. The Qur'an at several places has addressed the disbelievers of Makkah, saying, "A Sign of the torment that visited this wicked people on account of their misdeeds still exists on the highway, which you see night and day during your trade journeys to Syria." (AI-Hijr: 76; As-Saftat: 137). Today it is being admitted with near certainty that the southern end of the Dead Sea came into being as a result of a violent earthquake when the area in which Sodom, the central city of the people of Lot, was located sank underground. In this part there are still signs of some submerged habitations. Exploratory attempts are being made with the modern diving apparatus but the results are still awaited. (For further explanation, see E. N. 114 of Ash-Shu`araa A'raf.
*60) For the Islamic punishment of sodomy, see E.N. 68 of Surah Al 191.