Responsa for Bava Batra 94:4
לאפוקי מדרב דאמר רב לא שנו אלא דאמר ליה לך חזק וקני אבל בשטר קנה
we do not accept it and we do not confirm his title to the land. What has he [R. Huna] told us [in this latter clause]? We already know as much from the following Mishnah: 'If a man buys a field from the sicaricon<span class="x" onmousemove="('comment',' Commonly taken to be a corruption of sicarii, non-Jewish brigands who infested Palestine after the war of Bar Cochba; more probably. however (v. Jast., s.v. [H]) a corruption of [G], the Imperial fiscus established in Palestine at that time. The Rabbis ordained that purchases of land from that source were null and void. V. Git. 55. ');"><sup>7</sup></span> and then buys it again<span class="x" onmousemove="('comment',' I.e., obtains from him a deed of transfer, without, however, paying him money. Git. 55b. ');"><sup>8</sup></span>
Teshuvot Maharam
A. Since his brothers were young when their father died, A cannot claim undisturbed possession as proof of ownership for the period since his father's death, and must furnish documentary proof or witnesses to the effect that he enjoyed undisturbed possession for three years before his father's death.
SOURCES: Pr. 119; cf. Asheri, Sanhedrin 3, 37.