[If] a Yisrael inherited from his maternal grandfather, a Levi, he does not redeem according to this order. And so, too, [if] a Levi inherited from his maternal grandfather, a Yisrael, he does not redeem according to this order. As it says (Lev. 25:33): For the houses of the cities of the Leviim — unless he is [both] a Levi and in the cities of the Leviim; [these are] the words of Rabbi. The Sages, however, say: These matters were stated only concerning the cities of the Leviim. We may not make a field into a clearing, nor a clearing into a field, nor a clearing into a city, nor a city into a clearing. R’ Eliezer said: To what does this apply? To the cities of the Leviim. But in cities belonging to Yisraelim we may make a field into a clearing, but not a clearing into a field; [and we may make] a clearing into a city, but not a city into a clearing; lest they destroy the cities of Yisrael. The Kohanim and the Leviim may sell at any time, and redeem at any time; as it says (Lev. 25:32): The Leviim shall have an eternal [right of] redemption.