Theres a gemorah in kesubos (110b)that says “someone who lives in chutz laaretz is like they have no G-d”. BUt when the rambam quotes the gemorah he quotes it as “Someone who LEAVES eretz yisroel is like they have not G-d”.The rambam had the same girsa as the shita mekubetzes. The rosh in moed katan says that one is never allowed to leave eretz yisroel to tour. THe mishnah brura (531:14) says that one is allowed to leave eretz yisorel to perform a mitzvah.
Look at the sefer Whats bothering Rashi 159-161 Parshas behar. I found my info there.