Why is Eretz Yisrael called "Eretz Tzvi"? What does this mean exactly? Why? and Where does it say this?
Yirmiyahu Hanavi (Jeremiah the prophet) calls The Land of Israel "tzvi": (Jer. 3:19)
וְאֶתֶּן-לָךְ אֶרֶץ חֶמְדָּה, נַחֲלַת צְבִי
I give thee a pleasant land, the goodliest (tzvi) heritage...
Since the word tzvi also means a deer, the gemara asks (Kesubos 112a):
R. Hisda stated: What [was meant] by the Scriptural text, I give thee a pleasant land, the heritage of the deer? Why was the Land of Israel compared to a deer? — To tell you that as the skin of a deer cannot contain its flesh so cannot the Land of Israel contain its produce.
Another explanation: As the deer is the swiftest among the animals so is the Land of Israel the swiftest of all lands in the ripening of its fruit.