What is this Pasuk coming to add to the previous Pesukim?
Rashi and Ramban #1: It is a La'av on purchasers who fail to return the fields to their owners in the Yovel. 1
Ramban #2 (citing the Rambam): It is a La'av on the seller or on the purchaser not to stipulate that they are selling or buying the field permanently. 2
Ramban #3 (citing the Toras Kohanim): It is not a La'av, but a reason for the Mitzvah of Yovel, as if to say 'Enact the Yovel among yourselves, and don't be upset about it, since the land belongs to Me and I don't want it to be sold permanently like other sales'. 3
What is the meaning of "li'Tzemisus"?
Rashi #1, Targum Onkelos and Targum Yonasan: It means for an indefinite period, or permanently.
Rashi #2: It means 'cut off' - One may not cut oneself off from one's ancestral property in a way that one no longer redeem it. 1
See also Ibn Ezra.
What are the connotations of the phrase "ki Li ha'Aretz"?
Rashi: Do not begrudge having to return the fields, since they are not yours anyway.
Seforno: It means that Eretz Yisrael is the property of Hashem. 1
And what is the meaning of the phrase "Ki Geirim ve'Soshavim Atem Imadi"?
Rashi (in Divrei ha'Yamim 1, 29:33): It means 'You have no portion or inheritance in the land ... ; You are only allowed to sojourn in it'. 1
Ramban (citing the Toras Kohanim): It means 'Don't consider yourselves the main owners of your field; because you are with Me. 2
Seforno: Refer to 35:23:3:2*.