Responsa for Bava Batra 70:7

אמר רב יהודה אמר רב ישראל הבא מחמת עכו"ם הרי הוא כעכו"ם מה עכו"ם אין לו חזקה אלא בשטר אף ישראל הבא מחמת עכו"ם אין לו חזקה אלא בשטר אמר רבא ואי אמר ישראל

which would expose the mortgager to unfair loss? But the fact is that he can protect himself by lodging a protest within three years; and so in this case also he can protect himself by lodging a protest within three years. Rab Judah said in the name of Rab: A Jew who derives his title from a non-Jew is on the same footing as a non-Jew:<span class="x" onmousemove="('comment',' In the matter of hazakah. ');">¹²</span> just as a non-Jew cannot prove his right save through producing a deed of sale,<span class="x" onmousemove="('comment',' It is assumed that a Jew is afraid to protest against the occupation of his land by a non-Jew, and therefore three years' undisturbed occupation confers no hazakah on the latter. ');">¹³</span> so the Jew who derives his title from a non-Jew [to a field originally belonging to a Jew] cannot prove his right save through producing a deed of sale.<span class="x" onmousemove="('comment',' Given by the original Jewish owner to the non-Jew, even though both he himself and the non-Jew have enjoyed undisturbed occupation for three years. ');">¹⁴</span> Said Raba: If, however, the Jew pleads,

Teshuvot Maharam

Teshuvot Maharam