G-d bound the Land to the great mitzvah of milah (circumcision) by an everlasting covenant and equated milah, a mitzvah carried out right on the body, with Eretz Yisrael, which a Jew must be right inside: “I will sustain My covenant between Me and between you and your descendants after you throughout their generations, an eternal covenant. I will be a G-d to you and to your offspring after you. To you and your offspring I will give the land where you are now living as a foreigner. The whole Land of Canaan shall be your eternal heritage, and I will be a G-d to your descendants.” G-d then said to Abraham, “As far as you are concerned, you must keep My covenant – you and your offspring throughout their generations. This is My covenant between Me, and between you and your offspring, that you must keep. You must circumcise every male.” (Gen. 17:7-10)
Following is Bereshit Rabbah, 46:9: R. Yuden says, There are five [conditions here]: If your offspring receive My Divinity, I shall be your G-d and patron, and if not, I will not be your G-d and patron. If they enter the Land they shall receive My Divinity, and if not, they shall not receive My Divinity. If they perform milah, they shall enter the Land... If they accept the Shabbat, they shall enter the Land... Here, G-d decreed the connection between the Land and mitzvot. Only if Israel enter the Land do they receive G-d as their L-rd and Master. Outside the Land, they live under the nations and their harmful cultural influence. This involves Chilul Hashem, because when we live among the nations, under their rule, the nations' gods and culture enjoy superiority. Moreover, the Torah is adulterated by alien, non-Jewish ideas. G-d's becoming Israel's Master is also conditional on their accepting milah, a fundamental mitzvah, whose linkage to a Jew's actual body makes it an inseparable part of him. As our sages said of King David (Menachot 43b): Israel are beloved in that G-d surrounded them with mitzvot: tefillin on their heads and arms, tzitzit on their garments and mezuzot on their doors... When King David entered the bath house and saw himself standing naked, he said, “Woe to me that I stand naked without mitzvot.” Once he recalled the milah on his flesh, he calmed down. G-d wished the Jew to be surrounded with mitzvot every single moment of his life, so that he would always be holy and complete. He, therefore, established a mitzvah for his body to be an essential part of the person himself. That way, he would always be accompanied by a mitzvah. Likewise, G-d wished Israel to dwell always within a mitzvah. He, therefore, established the mitzvah of living in Eretz Yisrael. Thus, G-d tied the mitzvah of milah to Eretz Yisrael, and together, they were the first brit, or covenant, that G-d forged between Himself and Abraham, father of the nation.
G-d feared leaving the Jew free of mitzvot even a single moment. Not only would that leave him without holiness, but he would be exposed to the influence of the nations and the alien culture. G-d, therefore, affixed milah upon the Jew's flesh so that he would always be accompanied by a mitzvah. Milah is a mitzvah which enters a Jew's body, and Eretz Yisrael is a mitzvah into which a Jew enters. Why were both necessary? So that Israel would always be set apart from the nations, and so they would thereby safeguard their holiness completely and properly. For that reason, Israel could not enter the Land until they were circumcised, because milah and Eretz Yisrael are linked to each other through their keeping the Jew separate.
G-d ordained that Jews must perform circumcision, and in practice there are two types, one applying to the foreskin, the other to the heart. Of the first it says, “Ye shall be circumcised in the flesh of your foreskin” (Gen. 17:11), and of the second, “Circumcise the foreskin of your heart” (Deut. 10:16). Circumcision serves to soften man's pride, his physical and psychological strength, the arrogance of, “My power and the might of my hand has gotten me this wealth” (Deut. 8:17). Circumcision serves to complete the Jew. As long as he is uncircumcised, he is flawed, as though missing part of his body. This holds a great moral lesson. When a Jew gives up something of himself, that is precisely when he becomes perfect and complete. Before Abraham's circumcision, G-d said to him, “Walk before Me and you shall be perfect” (Gen. 17:1). Our sages comment (Nedarim 31b), “Great is circumcision, for with all the mitzvot Abraham performed, he was not called 'perfect' until he was circumcised.” Rashi comments, “As long as your foreskin is in place, you are flawed.” And Nedarim 31b further teaches, “Great is circumcision, for if not for it, G-d would not have created the world: “Thus says the L-rd: 'If not for My covenant [brit] day and night, I would not have set Heaven and Earth in motion' (Jeremiah 33:25)”. The reason circumcision is related to in this way is clear. It is G-d's mark that man has subjugated his body and his energies to Him. It is also clear that everything said regarding circumcision of the foreskin applies to circumcision of the heart. Both act to weaken man's arrogance and lust, suppress his passions and subjugate him to the service of G-d.
We are commanded to circumcise the hard shell that prevents man from feeling mercy, kindness and justice, for only these can bring him to humility, refinement and accepting G-d's yoke. This idea is alluded to by, “The L-rd has sought Him a man after His own heart” (I Samuel 13:14), i.e. a man with a heart like G-d's. The person who denies G-d's nature and decrees and rejects the yoke of Heaven will say, “It is my own life and my own body.” This fool does not understand that every sin he commits corrupts his soul and will ultimately lead him to hurt others through his false views. Through worshiping himself and pampering his physical cravings and desires, he will necessarily arrive at a situation in which his selfishness and arrogance dominate him, until he is enslaved to his body and his lusts. [For him, this week's Parasha points out that asides from the mitzvah of circumcision, applying to heart and foreskin, there is also another way to achieve the humbling of the heart: suffering of the body, as seen in the example of the leper].
Solomon said: Why is this leper purified by the highest of the high and the lowest of the low – by cedar wood and hyssop? To teach that if a person elevates himself like a cedar tree, he is stricken with leprosy; and when he humbles himself like hyssop, he is healed by hyssop (Yalkut Shimoni, Vayikra 559). Whoever suffers learns how weak and lowly he is. His arrogance and selfishness are erased, because he must lift his eyes to Heaven for salvation. Achieving humility and ridding oneself of evil conceit are one's very mission on this earth, and by such means one is spiritually magnified and exalted. Moreover, only through one's own suffering can one understand the suffering of others and learn empathy for the sick and the needy. The more severe and painful a person's suffering, the more his own arrogance is broken down. G-d decreed that Moses must take blood from the milu'im ram and place it on the right ear lobes, right thumbs and right big toes of Aaron and his sons [during their inauguration for service in the Tabernacle]. HaMidrash HaGadol (Lev. 8:24) asks, “Did Aaron and his sons need blood on their thumbs and toes? Rather it was done to teach them how to purify lepers.” The leper, as well, had blood placed on these same spots. Yet, why precisely here during the milu'im did G-d establish this lesson? The answer is that, also regarding the leper, we find the importance of lowliness, which is a condition for trusting in G-d. After all, leprosy struck in response to ten sins (Vayikra Rabbah 17:3), or eleven (Bamidbar Rabbah 7:5), and among them were arrogance and Chilul Hashem. Because Aaron was not humble enough to act with complete trust in G-d and self-sacrifice, and to blot out the Chilul Hashem [regarding the sin of the golden calf], G-d rendered him as if smitten with leprosy for his arrogance and the Chilul Hashem. I said previously that the world's having been created in Hebrew (Bereishit Rabbah 31:8) means that Hebrew did not emerge by itself via a historic process like other languages. Rather, it was “ready-made”, “created” by G-d alone. Thus, every word holds secrets and allusions, and Hebrew words are tied to one another by moral themes. Take note that mum (hebr.: blemish), and tamim (hebr.: perfect) come from the same root. Even so, they are opposites, as is G-d's way with the Hebrew language. This teaches that whoever is imperfect, spiritually blemished, will be smitten with a physical blemish. In this regard, G-d hinted to Aaron: because you were not perfect, you need the milu'im. Moreover, you must conduct yourself like the leper who has been smitten physically for not behaving with spiritual perfection. Mum and tamim are separated only by sin. In circumcision, mum becomes tamim through the removal of the foreskin.
Israel, by circumcising themselves physically and spiritually, will merit to destroy the nations. Yalkut Shimoni (Tehillim 875, on Ps. 118:10-12) comments, “Three times it says 'they swarm around me', corresponding to the three times Gog and Magog are destined to attack Jerusalem.” Three times Gog and his men will attack Jerusalem, yet all three times, “I shall destroy them [“amilam” – hinting at milah, circumcision].” This will happen by virtue of our circumcising body and heart.