Take a bit of water and wash your feet
Avraham assumed that the angels were Arabs who worship the dust on their feet, and made certain that no idolatry would enter his home.
The Arabs in the time of Avraham worshiped the dust of their feet. This sounds incredibly strange – what on earth could possibly be the reason for this? R. Yaakov Emden explains this behavior based upon the concept taught in Bereishis, “You are dust, and to dust you shall return.” Man is dust. Thus, the Arabs worshiped the dust of their feet. Explaining this is difficult. What exactly was the nature of this worship? What did they believe and why did they act this way?
The Gemara gives us some insight into the modes of worship of other idolaters as well. Baal Peor is mentioned often in the Torah. What was Baal exactly? The followers would eat and drink laxatives, so that their stools would grow soft. They would then sit before the idol and relieve themselves. This was the way to worship Baal Peor. The Gemara tells us that Jews only worshiped idols (such as Baal) in order to rationalize to themselves engaging in gilui arayos (illicit sexual behavior) in public. In other words, the Jews did not deeply believe that the idol was a true god, but worshiping it did something to make their psyches more comfortable with the idea that they could engage in giuli arayos. Why on earth should defecating in front of an idol have such an effect on a person?
We will answer these two queries with a look at a Midrash.
Avraham was working in his father’s idol store, and people would enter. Says the Midrash, “One man entered and asked, ‘How much is that idol?’ Avraham replied, ‘Three maneh.’ Then Avraham would ask the man, ‘But how old are you?’ The man said, ‘Thirty.’ Avraham replied, ‘Can your ears hear what is coming from your mouth? This idol was created yesterday, and you wish to worship it?!’ Another man entered and asked the price of a second idol. ‘Five maneh,’ Avraham told him, and then he asked, ‘How old are you?’ ‘Fifty,’ the man replied. So again, Avraham said, ‘Can your ears hear what is coming from your mouth? This idol was created yesterday, and you wish to worship it?!’”
I have several questions on this Midrash. Firstly, why is the price of those idols germane to the Midrash? The Midrash does not record Avraham wishing them good morning, which one is obligated to do even toward an idolator! This, of course, is because it has nothing to do with the message of the Midrash, and therefore is omitted! But then, why is it important that they asked the price of the idol? And why was it that the Midrash tells us of people asking for prices related to their age? The thirty-year-old’s was three maneh, the fifty-year-old’s, five maneh – surely this is not a coincidence! Lastly, and most importantly, were these people completely stupid? Everyone knows that the idol was created recently when they enter an idol store! In fact, they chose the idol store that they found had the best idols. So when they came in, they must have known that the idols had not been there from the beginning of Creation. There, idols clearly represented a form of worship. So, what changed? What was Avraham’s argument that was suddenly so convincing?!
The answer to this question answers all of our questions. Idolatry was about worshiping oneself, in a sense. The fellow who went to the bathroom on his idol made a loud statement: I can do anything I want. Even in front of my idol. He was also showing his lowliness. You see, if someone is entirely insignificant, then nothing that he does really makes a difference. “I am nothing” and “I can do whatever I wish” are essentially the same statement. Those who worshiped idols essentially worshiped themselves. They did what they wanted to do when they wanted to do it.
The Jews did not worship idols out of an honest search for truth. They were drawn after that philosophy by their drive to rationalize any behavior. In our times, we see that those who can explain that man is no more than an evolved paramecium can then rationalize any sort of aberrant behavior, for, after all, who cares what man does in the privacy of his own home any more than what a rat does in the privacy of his own sewer?
Avraham’s customers would buy idols that related to their stage and state in life. If they were fifty, the price of their idol would have to match that, for they were “celebrating man,” in today’s parlance. Avraham replied to them, “But your whims are not eternal. You were born only fifty years ago, and your whims were born yesterday!” Avraham inspired his customers to seek the eternal truths, and not to worship the dust of their feet.
We live in a society where we are taught that the highest of values is the pursuit of happiness. We are taught to dream of what we can all want, and then build toward it. How often are we told that what we want does not really matter? How often do we hear that we are not here to worship ourselves – to give in to our every whim? It is the Jew who brought this idea in to the world. We are here to answer a calling more deep and noble than the fleeting thought. The Jew tells the world that life is not only about what we may or may not want, but about choosing right over wrong, good over evil, and truth over falsehood.
Man is made of dust, but he also has a soul. His body will go back to dust as his soul ascends to its maker. Arabs in the time of Avraham worshiped the lowest part of man, for they were essentially worshiping themselves. Man is dust, so they worshiped dust. Avraham taught us all that man is also divine, and thus, he ought to worship Hashem.
 One wonders how we can say that Avraham assumed that they were Arabs, when the Torah traces the lineage of the Arab people to Yishamel explicitly (Bereishis 23:16)? R. Ovadiah Sforno explains that they were “like the Arabs that we see today,” but they were not, themselves, Arabs.
 Hagahos to Bava Metziah 86b. Other reasons are offered. R. Yeshaya Halevi Hurwitz (Sheloh) explains that since they worshiped the sun, they also worshiped the scorched sand, and Maharal (in Gur Aryeh) says that it was because they were tent-dwelling travelers who did not believe in settling down. R. Yaakov Loerberbaum (the Nesivos) (in his Emes Liyaakov on Talmudic Aggados, to Bava Metziah, ad loc.) explains based upon the Rambam’s explanation of the word regel as “result,” that they believed that they were the cause of their successes, while the truth was, their efforts were creating no more than fleeting dust.
 Sanhedrin 64b
 Ibid., 63b
 Seder Eliyahu Rabbah, ch. 6. This is from a manuscript quoted by R. M. M. Kasher in his Torah Shleima to Lech Lecha 15:7 .
 Maharam Schiff in Drushim Nechmadim, Tehillim 115:5 (published in the Vilna Shas after his commentary to Chullin) explains that it certainly was not that they believed that this actual form was the god, but rather that it represented the god’s form at a specific instant in time. [He thus explains that when David wrote, “They have a mouth, but they cannot speak; eyes but they cannot see…” he was saying, If those idols really represented a power, then the power would animate the idols. After all, man is the image of Hashem, and thus, the power of Hashem causes him to be animated! It is interesting to know, then, according to Maharam Schiff, how we are to understand the animation of the animal kingdom. There is much material regarding this in sources, but this is not its place.] See also Radak to Tehillim 115:4, where he explains that while the theologians did not believe in the idol as any more than a representative of a particular idea, the uneducated masses began to understand these idols to be the god itself. See also Aggados Eliyahu (R. Eliyahu Hakohen, author of Shevet Mussar) to Yerushalmi, Kiddushin chapter 9, paragraph 4, where he explains (based upon Avodah Zarah 41b regarding the idol Dagon) that idol worshipers worshiped spiritual forces, and they believed that the spiritual force that they worshiped would come and dwell in the idol itself, making that its home. He explains that this is why they would call out in prayer to the idol itself.