Just passing through
נעברה-נא בארצך לא נעבר בשדה ובכרם ולא נשתה מי באר דרך המלך נלך לא נטה ימין ושמאול עד אשר-נעבר גבולך: ויאמר אליו אדום לא תעבר בי פן-בחרב אצא לקראתך
Please, let us pass through your land. We will not pass through field or vineyard. We will not drink the water from [our] well. [Rather], we shall walk through the path of the king. We will not veer right or left until we’ve passed through your border. Edom said to him: “You shall not pass through my land, lest I encounter you with the sword”
After almost forty years of traveling through the wilderness, the Jewish people finally received permission to enter the land of Israel. As they approached its borders, they encountered the land of Edom, their cousins and enemies. Edom, the nation of Yaakov’s brother Eisav, bore the same jealousy and hatred towards the Jews that their ancestor had towards his brother. The Jews requested permission to pass through the land. They promised not to tread through Edom’s fields and vineyards, and to purchase food and drink from the populace. Their request for permission was denied. Seemingly, the Jews were promising that their passing through the land would not only not be damaging, but even profitable. As well, the nation of Edom seemingly denied entry as they predicted their emotions would lead to fighting and bloodshed. However, is there another way to understand this exchange?
In Jewish law, land can be acquired in three ways: with money, a sale deed, or what is known as chazakah. The first two are clear, but what is chazakah? Essentially, it’s an act by the purchaser which expresses ownership. For example, building a fence around a field. Only the owner would do that. If this act of chazakah was done with the owner’s permission, with the intent to transfer ownership, the land now belongs to the person who performed the chazakah. There are other methods of chazakah, and some of them are subject to a dispute.
What if the purchaser simply walked across the length and width of the land? Perhaps the purchaser is showing ownership over the area that they traversed. This method of chazakah is a matter of dispute. Rabbi Eliezer says that it works, and the Sages disagree. What is the reasoning of Rabbi Eliezer? The gemarra says that he learned it from Avraham. Hashem told Avraham that he would acquire the land of Israel, and that he should walk across its length and width. You see then that this is a method of acquisition.
The Sages reject this source, as that command wasn’t about acquisition. Rather, they say it showed how dear Avraham was to Hashem, as this traversing of the land would make it easier for his descendants to conquer it. How was this so? By traversing the land, it would make his future descendants look like they were inheriting it from him, rather than appearing like they were stealing from the inhabitants. If the latter were the case, there would have been room for heavenly forces to influence their defeat. However, the gemarra clarifies that the Sages agree to Rabbi Eliezer in the case of a path that goes through a vineyard. Since that path is exclusively made for traversing, by doing so it effects ownership.
With those laws in mind, subtext in the exchange between the Jewish people and the nation of Edom becomes more apparent. Geographically, the land of Edom is part of the lands of the ten nations which were promised to Avraham’s descendants. As such, Edom was concerned that the Jews’ intent in passing through the land was in order to effect an acquisition of it. To alleviate this concern, the Jews said they wouldn’t pass through any field or vineyard. This was to include even the paths of the vineyards, which do in fact effect ownership. They would only walk through the regular paths that the king would allow, which according to the Sages wouldn’t be a valid chazakah.
How did the nation of Edom respond? They said they will not grant passage, lest they encounter the Jews with the sword. At first glance, this seems like an admission that as the Jews pass through, the Edomites will inevitably wage war, causing bloodshed. However, according to this gemarra about Avraham, there could be a different intent. Perhaps Edom was saying that in the future, not now, they might need or want to wage war against the Jews. However, if Edom allowed the Jews to pass through their land, this would be to their disadvantage. Just like Avraham traversed the land of Israel, making it easier for his children to conquer the land, so too the descendants of this generation. If the Jews passed through the land of Edom, it would enable their own descendants’ victory in future battles against Edom. This is why Edom refused any passage whatsoever, forcing the Jews to take another course.
 Based on Meshech Chochmah to Numbers 20:17,18
 Cf. Targum Onkelos ad. loc., who as usual translates נא as כאן, now
 Contrary to the implication of the popular Yaakov Shwekey song, the simple reading of the verse tells us that the path of the king refers to the king of Edom, not to Hashem. However, there are some chassidishe sources which also read the verse to be referring to the path of Hashem, such as Likkutei Moharan 20:10, Sefas Emes to Numbers 20:14 from the year 5639, Agra DeKala ad. loc., Be’er Mayim Chaim to Genesis 3:24
 Numbers 20:17,18
 See Sifrei Bamidbar § 69, brought by Rashi to Genesis 33:4: הלכה היא בידוע שעשו שונא ליעקב. It’s probably more accurately הלא בידוע, as demonstrated by Yalkut Shimoni Beha’alosecha § 722. Although, one could argue that that aphorism is specifically referring to Eisav and Yaakov, and not their descendants
 Rashi to v. 17
 Kiddushin 1:5
 Bava Basra 3:3
 Ibid 100a
 Genesis 13:17
 Rashbam ad. loc. See Pesach Einayim ad. loc.
 See Rashbam and Ramban ad. loc.
 Genesis 15:18-21 with Rashi and Bava Basra 56a with Rashbam s.v. כל שהראהו
 Lekach Tov to Numbers 20:17
 See Tosafos to Bava Basra loc. cit.