Why is it called "tevel" (an admixture)? For it is an admixture of all. For with all the lands, one possesses what the other does not, but Eretz Yisrael lacks nothing, as it is written (Devarim 8:9) "a land where not in constraint shall you eat bread. You shall lack nothing in it."
Variantly: Why is it called "tevel"? Because of the "tavlin" ("seasoning") in its midst. Which "tavlin" is in it? — Torah, viz. (Eichah 2:9) "Among the nations there is no Torah" — whence it is seen that the home of Torah is Eretz Yisrael.