(Baraisa): One may not redeem it onto coins that are in Bavel nor onto coins of Bavel that are here.

(The Gemara explains): 'Not on coins that are in Bavel' means coins of Eretz Yisrael that are in Bavel (since they cannot be spent there). 'Not on coins of Bavel that are here' means Bavel coins in Eretz Yisrael.

Let us say that if the ways are open (meaning that there is frequent travel between Bavel and Eretz Yisrael) it may be used to redeem and if not, it may not.

Question: (Even if there is frequent travel) can they be spent here?

Answer (R. Avin): All currencies could be spent in Yerushalayim (in order to make it easy for Jews coming for the three festivals from throughout the world), as the pasuk states (Tehillim 48:3), "Beautiful for situation, the joy of the entire earth''.

I might have thought that if he had money in Har HaMelech and Katzra (from which there isn't frequent travel), he could redeem onto them; but the pasuk states (Devarim 14:25), "and bind up the money in your hand'' - 'in your hand' means under your control. (Note: This entry follows Rav Chaim Kanievski. Others explain that these places were close to Yerushalayim but under Roman rule, not allowing travel to and from them.)

Question (R. Yona): If his money pouch fell into a pit and it contains 1 million zuz and he could spend half a million on workers to bring it out the pit; do we allow him to redeem onto the other half even while it's in the pit? (The Gemara leaves this question unanswered.)