“Let some water be brought, and wash your feet, and relax under the tree.”[18:4]
We see that Avraham wanted his visitors to wash their feet immediately, before entering his house. Rashi explains that Avraham thought that the three angels, who appeared to be ordinary men, were idolators from the region who worshipped the dust of their feet. He was therefore careful to ensure that they did not bring the objects of their idolatry into his home. Rashi goes on to say that Avraham’s nephew Lot was not careful about this, and therefore he brought two of these same guests into _his_ home before having them wash their feet.
If we look, however, at the verse later where Lot brings in the guests [19:2], Rashi provides a very different explanation. Although Avraham was extremely careful that they do so, it is, of course, quite normal for people to wipe the dust off their feet before going into someone’s home. So why, then, did Lot deviate from this norm? The answer is that the evil people of S’dom did not allow people to shelter guests, leaving the guests to sleep outside where the residents could rob them at will. Rashi tells us that Lot was therefore concerned that if he would bring the guests in with their feet already clean, the people of the city would accuse him of having sheltered guests for several days. By having them go into his house with the dust still on their feet, anyone would see that these people had just come from the desert.
The Avnei Azel says that there is no contradiction between the two explanations offered by Rashi. When discussing the verse regarding Avraham, Rashi accentuates the difference between Avraham and Lot, but both reasons are correct — the first is a prerequisite for the second.
Had Lot been careful to keep any possible idolatry out of his home, then he would have been obligated to think only about that, and not to worry about what the people of S’dom might think. A person is supposed to be willing to give up his life in order not to worship idols, and the Avnei Azel says that were Lot careful about objects of idolatry, he should have been willing to risk his life to keep them out of his home. Therefore we first need to know that Lot was not concerned about this, before understanding why he brought in his guests in a way which was unusual in any case.
The Avnei Azel goes on to point out that one could also say as follows: that had the people of S’dom known that Lot, like his uncle Avraham, was concerned about the prohibition of idolatry, then they would have concluded that this was the reason the people were entering his house with clean feet, rather than accusing Lot of sheltering guests for several days without telling them. Given that Lot was worried about this accusation, it is clear that the people of S’dom already recognized him as someone who had never been careful about this at all.
When a person adopts a set of principles and sticks by them, then other people will respect and honor him or her for adhering to them. People will, however grudgingly, understand that those principles guide the individual to behave in a certain way. But if a person is careless with his or her principles, then if one day he or she chooses to observe them in a difficult situation, people will not say that this is a moral choice — they might rather assume the worst!