Who will dwell, and in what shade?
Rashi: Those who already dwelled in the shade of the Levanon, to which Yisrael and the Beis ha'Mikdash were compared, and they were exiled from it - they will return to it.
Radak #1: Yisrael will return to their land, and dwell in the shade of Hashem.
Radak #2: "Yashuvu" means that they will rest, like "b'Shuvah va'Nachas" (Yeshayah 30:15).
Malbim: Those who want to dwell in the shade of the Levanon (Beis ha'Mikdash) will return. This is a Nevu'ah that many of the exiles will return to Eretz Yisrael and fix their residence in Eretz ha'Kedoshah, in the shade of Levanon.
What do we learn from "Yechayu Degen"?
Rashi: They will keep grain, and enter it in storehouses.
Radak #1: They will constantly give life to themselves via Hashem's Mitzvos, like grain, which primarily sustains man. The prefix Kaf (for comparison) is omitted (it should say k'Degen). We find like this - "Lev Soma'ech Yeitiv Gehah" (Mishlei 17:22; it means k'Gehah).
Radak #2: The nature of grain will change when the redeemer comes. It will survive permanently, like vines; they will need to plant it only once, like a vine. Chazal (Kesuvos 111b) discussed changes in wheat in the future.
Malbim: They will have grain for bread for their houses.
What do we learn from "Yifrechu cha'Gefen"?
Radak: Do not say that their good will cease, just like an olive-tree ceases and dries, until it is replanted. No - they will sprout like a vine. After its fruits are gathered, it does not cease and dry. Rather, it sprouts every year.
Malbim: A vine spreads to afar. They will multiply and make fruits.
What is the meaning of "Zichro k'Yein ha'Levanon"?
Targum Yonasan: Like the remembrance of sounds of the trumpets on old wine poured in the Beis ha'Mikdash. They blew trumpets at the time of Nesachim when the Leviyim sang.
Radak: "Zichro" is its smell, like "Azkarasah la'Shem" (Vayikra 6:8). The smell of wine of the vine, to which Yisrael are compared, will be like the smell of wine of Levanon, which is good. Asaf ha'Rofei says that wine of Levanon, Chermon, Harei Yisrael and Yerushalayim, Harei Shomron and of Kaftor Egypt, they are superior to others for smell, taste and healing. Smell is a Mashal for good repute that Yisrael will have amidst all nations in the future.
Malbim: The memory of Levanon will be like its wine. Also those who do not return to live in Eretz Yisrael, they will always remember Levanon, like they remember that its wine was very good. One who drinks it does not forget it. So they will remember "ha'Har ha'Tov ha'Zeh veha'Levanon" (Devarim 3:25, i.e. the Beis ha'Mikdash) in all their prayers, and raise Yerushalayim above their greatest Simchah.
