Why does the Torah again repeat "Yovel hi"?
Ramban: It is a reason for the prohibition against planting and harvesting mentioned in the previous Pasuk.
Torah Temimah (citing Rosh Hashanah, 40b): It comes to include Chutz la'Aretz in the Din of Yovel, with regard to the releasing of one's Avadim.
What are the ramifications of the phrase "Kodesh Tih'yeh lachem"?
Rashi: It teaches us that, like Hekdeh, the Kedushah of Yovel-fruits is transferred on to whatever one purchases it with. Unlike Hekdesh however, the fruits themselves retain Kedushas Shevi'is. 1
Rashi: as Chazal derive from the word "Tih'yeh", 'be'Havayasah T'hei'.
And what are the implications of the words "min ha'Sadeh Tochlu ... "?
Rashi: Via the field, one may eat what is in the house. 1
Ramban #1 (citing Ibn Ezra): One may however, eat what the field produces by itself - just like in the Shemitah year.
Ramban #2: After prohibiting planting and harvesting in the Yovel because it is Kadosh, the Torah permits going into the field and eating the fruit together with the poor and with the animals, provided one desists from harvesting one's crops and grapes to bring in bulk onto the house or to place in the storehouses, as one does in other years.
Rashbam: It implies that one may eat from what is in the field, but not from what one has gathered into the house - illegally.
Seforno: Even though Hashem forbade the owner to plant, reap or gather in his produce from the field to the house, as he does in other years, He permitted him to eat from his fruit like anybody else - just like in the Shemitah-year. 2