Rashi #1, Targum Yonasan: [The first two teach that] he was exiled from his land to another land; the third means that Eretz Yisrael should hear Devar Hashem.

Rashi #2: The land that is the [ultimate] land of lands; it is the most important.

Rashi #3: Eretz Yisrael has three lands - Yehudah, Galil and Ever ha'Yarden.

Radak citing his father: Refer to 7:4:3:2.

Radak: Perhaps it is repeated to strengthen the matter. For this, matters are repeated two times, e.g. "Kol ha'Karev Karev" (Bamidbar 17:28), "Nachamu Nachamu Ami" (Yeshayah 40:1) or three times, e.g. "Heichal Hashem Heichal Hashem Heichal Hashem" (7:4), "Avah Avah Avah Asimenah" (Yechezkel 21:32). He calls out to the land, i.e. the people of the land, for it says "Kisvu" (verse 30. It must refer to the people!) The same applies to "v'Chol ha'Aretz Ba'u Mitzraimah" (Bereishis 41:57).