וְיֶ֨תֶר הַגִּלְעָ֤ד וְכָל־הַבָּשָׁן֙ מַמְלֶ֣כֶת ע֔וֹג נָתַ֕תִּי לַחֲצִ֖י שֵׁ֣בֶט הַֽמְנַשֶּׁ֑ה כֹּ֣ל חֶ֤בֶל הָֽאַרְגֹּב֙ לְכָל־הַבָּשָׁ֔ן הַה֥וּא יִקָּרֵ֖א אֶ֥רֶץ רְפָאִֽים׃
און דעם רעשט פֿון גִלעָד, און גאַנץ בשָן, דאָס קיניגרײַך פֿון עוֹגן, האָב איך געגעבן צום האַלבן שבֿט מנשה; די גאַנצע געגנט פֿון אַרגוֹבֿ – יענער גאַנצער בשָן װערט גערופֿן דאָס לאַנד פֿון די רפֿאים.
Or HaChaim
We also find a statement in Bamidbar Rabbah 7 that the East Bank of the Jordan is not a suitable place to erect the Temple, nor for the שכינה to settle. We have scriptural proof of this from Joshua 22,19, where it says that "if the land of your inheritance has become defiled (in your eyes i.e. the East Bank of the Jordan), cross over to the land of inheritance of G'd Himself, who dwells there in the Tabernacle and acquire an inheritance amongst us, etc." This tells you very clearly that there is a difference between the lands of Sichon and Og and that of ארץ ישראל proper. Perhaps this is the reason why Moses did not want to give each one of the tribes a share in those lands, and why he preferred that all of the tribes should accept their heritage on the West Bank which is holier. Compare what we have written on Deut. 3,13 on the words ההוא יקרא ארץ רפאים.
Rashi
ואת הרפאים AND THE REPHAIM — the land Og King of Bashan, of which it said, (Deuteronomy 3:13) “All that (Bashan) is called the land of the Rephaim”.
Or HaChaim
ארץ רפאים תחשב אף היא, it is also considered the land of the Rephaim, etc. Rashi says that the reason this land was called the land of the Rephaim was that the Rephaim used to live there at one time; however, this is not the land of the Rephaim G'd had promised to Abraham at the time. I cannot see what forces Rashi to arrive at this conclusion. Where did G'd ever say that these Rephaim were not included in the ones whose land G'd promised to Abraham? On the contrary, whenever Rephaim are mentioned it includes all the people known as Rephaim. I have seen that Rashi supports his theory by saying that his source is the wording of verse ההוא יקרא ארץ רפאים (Deut.3,13). The fact that the Torah stresses there "this is the land called the land of the Rephaim," suggests that only that part of the Bashan was the land G'd had promised to Abraham under the heading of "the land of the Rephaim." The extra word ההוא means that any other land in which the Rephaim lived at different times was not considered as "their land" (compare Rashi in Chulin 60). I am not persuaded by this proof. Why do we have to assume that the word ההוא in Deut 3,13 is meant to exclude other lands occupied by the people known as the Rephaim? Maybe the word is only meant to exclude the district called Argov seeing it is not called "land of the Rephaim?" Logic would dictate that the word ההוא is meant to indicate precisely what the Torah refers to, not something the Torah wants to exclude. After the Torah had told us that the Rephaim used to live in the land occcupied by the Bney Ammon and the Moabites (the descendants of Lot) at that time, the Torah mentions that these lands were really included in what G'd had promised to Abraham at the time. Furthermore, the word ההוא was not intended to restrict except to tell us that at the time Moses spoke these lands were no longer popularly known as the lands of the Rephaim but as the lands of Sichon and Og rather than as the lands of Bney Ammon and Moav. In fact, even at the time when G'd made the promise to Abraham these cities were not known as lands of the Rephaim as G'd had temporarily designated these cities as the inheritance of the descendants of Lot. Rashi (2,5) himself explains that Abraham who had been promised these lands by G'd, turned them over to Lot (temporarily) who went to Egypt with him becaus he did not reveal the secret of the husband-wife relationship between Abraham and Sarah.