Your claim is baseless. Knowing what scandal awaited him in front of his guests, and what ill-treatment awaited these guests from his own people, Lot was troubled on their account.The woeful day soon started when his people rushed towards him. They were impelled by their desires, rushing like one who has lost self-control. This was the reason for the distress Lot felt on his guests’ account.
When Lot looked at his people coming hurriedly towards his home, intent on abusing him and his guests,
he tried to arouse their upright nature and direct them to the opposite sex with whom healthy nature finds pleasure. He was even ready to give his daughters in marriage to those frenzied people to satisfy their maddening desires in a clean, pure way. All the connotations of purity,psychological and physical, are meant here. Lot’s daughters would provide a proper, sound and natural way for the satisfaction of sexual desire, arousing healthy feelings as well. It is a situation of complete purity, natural as well as moral and religious. Moreover, they are physically purer. The will of the Creator has provided a clean, pure place for the new emerging life.
Lot also tried to appeal to their fear of God, and their sense of propriety in providing hospitality to one’s guests.
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الَ يقَوْمِ هَـؤُلاءِ بَنَاتِى هُنَّ أَطْهَرُ لَكُمْ
(He said: "O my people! Here are my daughters (the women of the nation), they are purer for you...'') This was his attempt to direct them to their women, for verily the Prophet is like a father for his nation. Therefore, he tries to guide them to that which is better for them in this life and the Hereafter. This is similar to his statement to them in another verse,
أَتَأْتُونَ الذُّكْرَانَ مِنَ الْعَـلَمِينَ - وَتَذَرُونَ مَا خَلَقَ لَكُمْ رَبُّكُمْ مِّنْ أَزْوَجِكُمْ بَلْ أَنتُمْ قَوْمٌ عَادُونَ
(Go you in unto the males of the nation, and leave those whom Allah has created for you to be your wives Nay, you are a trespassing people!)
26:165-166
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Maududi:
By "my daughters" Prophet Lot might have meant either of the two things.
He might have referred to the daughters of the community as "ray daughters" because the relationship of a Prophet to his people is as of a father to his children.
But it is also possible that he aught have meant by this his own daughters.
Anyhow this could not have been an offer of adultery, for the succeeding sentence "..these are purer for you" leaves no room for such a misunderstanding. This makes it quite obvious that Prophet Lot admonished them in this way so as to turn them to the females for the lawful gratification of their sexual desires instead of seeking unnatural ways.
http://www.quran-wiki.com/ayat.php?sura=11&aya=78