I remember reading somewhere that the reason Yitzchak did not go to see Rivkah before engaging/marrying her (even though you are supposed to see the girl before engaging/marrying her per gemara kiddushin 41) was because he was not "supposed" to leave Eretz Yisrael.
1- Is there a source for this? 2- Why was Yitzchak not "supposed" to leave Eretz Yisrael?