What is "Tzeidah"?
Rashi: Its food. Radak - this is like "b'Yom Michram Tzayid" (Nechemyah 13:15).
What is the meaning of "Tzeidah Barech Avarech"?
Radak: Tziyon's grain and Peros will be blessed more than all of Eretz Yisrael 1 , for the honor of My house in it. Perhaps Eretz Yisrael 2 is called Eretz ha'Moriyah, for it was Revayah (satiated) after [Hashem's] honor dwelled there.
Malbim: The Brachah to Tziyon will spread and influence the entire land.
Pesachim 8b: There are not Ginosar fruits (they are unbelievably tasty - see Berachos 44a) in Yerushalayim, lest people say 'it was enough to come to Yerushalayim to eat the fruits', and then the Aliyah l'Regel would be Lo Lishmah! Perhaps Yerushalayim was most blessed in quantity, but other places had tastier Peros. (PF)
I did not find any source that Eretz Yisrael is called Eretz ha'Moriyah. Avraham was in Eretz Yisrael when Hashem told him to go to Eretz (i.e. Har) ha'Moriyah for the Akeidah (Bereishis 22:2)! Perhaps the text of Radak should say that Yerushalayim or Tziyon is called Eretz ha'Moriyah. (PF)
Why does it say "Evyoneha"?
Radak: Even the Aniyim in it will be satiated with food.
