Concerning Allah's statement,
وَجَاءهُ قَوْمُهُ يُهْرَعُونَ إِلَيْهِ
And his people came rushing towards him,
meaning, they made haste and rushed due to their delight of this (new young men).
Concerning the statement,
وَمِن قَبْلُ كَانُواْ يَعْمَلُونَ السَّيِّيَاتِ
and since aforetime they used to commit crimes.
This means that this did not cease being their behavior until they were seized (by Allah's torment) and they were still in the same condition.
قَالَ يَا قَوْمِ هَـوُلاء بَنَاتِي 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 other 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)
Allah said in another verse,
قَالُواْ أَوَلَمْ نَنْهَكَ عَنِ الْعَـلَمِينَ
They (the people of the city) said;"Did we not forbid you from entertaining any of the `Alamin!" (15;70)
This means, "Didn't we forbid you from hosting men (male) guests!"
قَالَ هَـوُلاءِ بَنَاتِى إِن كُنْتُمْ فَـعِلِينَ
لَعَمْرُكَ إِنَّهُمْ لَفِى سَكْرَتِهِمْ يَعْمَهُونَ
(Lut) said;"These (the girls of the nation) are my daughters, if you must act (so)." Verily, by your life, in their wild intoxication, they were wandering blindly. (15;71-72)
Then, Allah said, in this noble verse,
هَـوُلاء بَنَاتِي هُنَّ أَطْهَرُ لَكُمْ
(Here are my daughters, they are purer for you).
Mujahid said,
"Actually, they were not his daughters, but they were from among his nation. Every Prophet is like a father to his nation."
A similar statement has been reported from Qatadah and others.
Concerning the statement,
فَاتَّقُواْ اللّهَ وَلَا تُخْزُونِ فِي ضَيْفِي
So have Taqwa of Allah and disgrace me not with regard to my guests!
This means, "Accept what I command you by limiting the fulfillment of your desires to your women."
أَلَيْسَ مِنكُمْ رَجُلٌ رَّشِيدٌ
Is there not among you a single right-minded man!
This means, "Is there not a good man among you who will accept what I am enjoining upon you and abandon what I have forbidden for you!