Leviticus 25:23

And the land of Israel shall not be sold absolutely, for the land is Mine; for you are sojourners and guests with Me.

permanent ownership From “God our God shall cut them off” [Psalms 94:23]. The tav is part of the triliteral root (as in “divorce” [Hebrew: kritut] [Deuteronomy 24:1]).

The fundamental reason for these laws is that the land is Mine . Moshe himself said in his prayer, “God, you have been our dwelling place” [Psalms 90:1]. In other words: You are like an eternal dwelling place, into which “one generation passes away, and another generation comes” [Ecclesiastes 1:4].

AND THE LAND SHALL NOT BE SOLD IN PERPETUITY. “This is to declare a negative commandment affecting [one who refuses] to return fields to their [original] owners in the Jubilee, so that the purchaser should not retain it.” This is Rashi’s language. But if so, why does He warn about “selling” [saying, the Land shall not be ‘sold’ in perpetuity], when it should rather have said: “Thou shalt not buy in perpetuity”? Perhaps [the meaning of the verse is as if] it said, “and the Land shall not be sold to you in perpetuity” [and thus the prohibition refers to the buyer]. Similarly, they shall not be sold as bondmen is an admonition to the purchaser, that he must send forth to freedom [a Hebrew servant] in the Jubilee year, according to the plain meaning of the verse.
It is, [however], possible that the Land shall not be sold in perpetuity is a negative commandment referring to the seller, that he is not to sell it permanently by saying: “I am selling it to you forever, even for after the Jubilee.” For although the Jubilee [in fact] takes it out of his possession [despite his intention of buying it permanently], Scripture nonetheless admonishes the seller or both of them that they should not [attempt to] make their transaction in perpetuity, and if they did so stipulate, they transgress this negative commandment, and [additionally] it will be of no avail to them, for the land will return in the Jubilee. And so did Rabbi Moshe [ben Maimon] explain it. 11:1. And the reason for this prohibition [of stipulating a permanent sale, although such a stipulation is completely ineffective], is because it is well-known in human thought that if people take into account from the beginning of the transaction the number of years until the Jubilee, it will [in the end] be easier for them [i.e., for the purchasers, to return it in the Jubilee], but if one [intends to] buy it in perpetuity, one will find it very difficult to return. This prohibition, then, is similar to what the Sages have said: “That which the Merciful One said one may not do, if one does do, has no legal effect, but the transgressor is liable to the punishment of whipping because he violated the Royal decree.”
The correct opinion appears to me to be that this is not a negative commandment [for the transgression of which] one is liable to whipping. Rather, [the verse merely states] a reason [for the Jubilee], saying: “Observe between you [the law of] the Jubilee, and be not resentful about it, for the Land is Mine, and I do not want that it should be sold in perpetuity as [in the case of] other transactions.” This is the meaning [of the Rabbis’ interpretation] in the Torath Kohanim: 4:8. “And the Land shall not be sold ‘litzmithuth’ — permanently. For the Land is Mine — [therefore] be not resentful about it. For ye are strangers and settlers — do not consider yourselves the main [proprietors]. Ye are with Me — it is enough for the servant to be as his Master. When it is Mine it is yours.”
By way of the Truth, [the mystic teachings of the Cabala], the meaning of the expression for the Land is Mine [literally: “for ‘unto Me’ is the Land”] is like and they take ‘unto Me’ an offering. It is this which the Rabbis have alluded to here [by saying in the Torath Kohanim]: 4:8. “It is enough for the servant to be as his Master,” for the Jubilee will be applying [even] in the world. The person learned [in the mysteries of the Cabala] will understand.

והארץ לא תמכר לצמיתות. The legislation applies to land intended for cultivation..

כי לי הארץ, a reference that the region known as גליל, the earth is G’d’s. [specifically excluding the east bank of the Jordan, based on the letter ה in front of the word הארץ. Compare Torat Kohanim there. Ed.] כי גרים ותושבים אתם עמדי, in this very same גליל, which is not part of “He has given earth to man” (Psalms 115,16).