B"H
Why does H' make Moshe -- more than once, I think -- go up a mountain to look at the Land of Israel which he will never enter?
This seems cruel. Moshe was the holiest and most self-sacrificing person who ever lived, probably. Why did H' do it to him?
While there are various other answers to this question, I will highlight a few of them:
One simple answer is that Moshe wanted to see the land, and this is what Rashi (Devarim 3:27) suggests:
וראה בעיניך – בקשתה ממני: ואראה את הארץ הטובה (דברים ג׳:כ״ה), אני מראה לך את כולה, שנאמר: ויראהו י״י את כלא הארץ (דברים ל״ד:א׳).
וראה בעיניך [LIFT UP THINE EYES …] AND SEE IT WITH THINE EYES – Thou didst request of Me, (v. 25) "Let me see the good land"; I will let thee see the whole of it (not the good territory alone), as it is said, (Deuteronomy 34:1) "And the Lord showed him all the land" (cf. Sifrei Bamidbar 135). (Alhatorah translation)
Ralbag there elaborates and provides potential reasons why Moshe would have wanted to see it, namely that Moshe had heard a good report of it, and wanted to see some of that firsthand.
Another answer (given by Shadal to Bamidbar 27:13, and by Ibn Caspi to Devarim 3:27) is that this was a way of showing Moshe that he did not waste his efforts in bringing the nation to this point.
Minchas Yehuda to Devarim 3:27 provides a very original thought, noting that God had sworn that none of those that despised him would see the land (Bamidbar 14:23). Therefore, to make sure that no one would claim that Moshe was part of that evil group, God took him to see the land
Your premise is that God forced Moshe to go up the mountain and look at the land in some torturous fashion, driving home the point that he would never enter it.
I believe this is an incorrect premise. We can see from several of the commentaries that going up to the mountain to see the land was something positive, and perhaps even something that Moshe asked for.
Rashi explains that this was a partial fulfillment of Moshe's request. Moshe had asked אֶעְבְּרָה נָּ֗א וְאֶרְאֶה֙ אֶת־הָאָ֣רֶץ הַטּוֹבָ֔ה to cross over and to see the land. God responded by allowing him to see the land even though he would be unable to cross over into it.
וראה בעיניך. בקשתה ממני ואראה את הארץ הטובה אני מראה לך את כולה שנאמר ויראהו ה' את כלא הארץ
Similarly R. Yosef Bechor Shor explains that Moshe asked to cross and to see the land. God responded that He did not want to deny Moshe everything, so even though he would not cross, if he wants to see the land he can see it from the mountain:
ואם תאב אתה לראות שא עיניך וראה מכאן כי איני רוצה להשיב פניך מכל וכל אתה שואל לעבור ולראות הראיה תהיה לך ולא העברה שהרי עיקר שאילתך מפני הראיה כי לא תעבור והראה לו הקב"ה הכל דכתיב ויראהו ה' את כל הארץ
R. Yosef Ibn Kaspi writes that seeing the land was good for Moshe. After he worked so hard to get them there, if he didn't merit to enter it he at least merited to see it.
ושא עיניך. בעבור שמשה עמל בהעם הזה וכלה ימיו בם להכניסם לארץ לקח לו נחת רוח בראותו בעיניו הארץ ההיא אחר שלא זכה לקחתה זכה לראותה
The Ramban in his commentary says Parshas V'Zos HaBracha (Deut 34:1) the following:
(Source provided by Sefaria.org)
(Partial Quote)
וטעם המראה הזאת אשר הראהו בעבור שהיתה הארץ מלאה כל טוב צבי לכל הארצות ומאשר היה גלוי לפניו רוב האהבה שהיה משה רבינו אוהב את ישראל שמחו ברבות הטובה בראות עיניו:
The reason for [G-d] showing [Moshe Rabbeinu the land] because the land was filled with all that was good and pleasurable than all other lands, and being that it was known before Him [i.e. G-d] that Moshe Rabbeinu loved [the people of] Israel, he would be happy with seeing the great good [which G-d would be giving to the people of Israel] with his own eyes
Hope this is insightful!!
An unattributed source brought in the Ma'ayenei Shel Torah explains that HaShem allowed Moshe to see the Land as some form of consolation; while he would not be allowed to enter and traverse the Land at all, he would be able to survey the Land in its entirety. He goes on to add that Moshe's seeing the Land infused it with additional holiness. Moreover, had Moshe been allowed to enter the Land he would have infused the Land with such holiness that when the time for the exile came, HaShem would not be able to pour his wrath on the Land in lieu of the Jewish people, necessitating the destruction of Am Yisrael, God forbid.
I'm not religious, so from my point of view (which is a communication scientific one) the reports about events religions pass on are not true or false but they have certain narrative aspects which are certainly worth analyzing.
Moshe having to or being able to view the land of his dreams while having the knowledge of never being able to enter it triggers strong emotional responses in the people perceiving this narrative. They are likely to relate to this situation of hopeless longing.
This makes it way more probable to get passed on while the narrative develops during a tradition phase. Similar narratives which lack this aspect are less likely to get passed on, so this one "survives". I'm aware that religious people might believe that this text was conceived and never "developed", but I do not believe this. (If somebody feels offended by this, please forgive me, this is not my intention.) And even if we assume in judaism.stackexchange.com that the Torah was written directly by God and never changed, we should try to understand how He made it to be compelling to the people who read it. Then the same psychological mechanisms can apply which in other circumstances make a text survive an evolutionary process.
Concerning the aspect whether Moshe was forced to look at the land or whether he wanted to: This is of minor importance (viewed from this angle). Both options trigger an emotional response. In the one case the response was about the hard to understand cruelty of making someone long for something even more. In the other case about the benevolence of Hashem for having the generosity and grace to at least showing Moshe what he longs for. So consequently the narrative often is told without clarifying this aspect (hence leading to this question).
So from this point of view, the answer is: The narrative about Moshe contains this scene (or these scenes) to raise emotional responses. Narratives showing such features have a greater chance of being passed on through the generations. This also makes the whole narration more likely to provide an emotional help for people in longing situations.
