BT Ber 25b(47) :כל עשרה רשותא אחריתי היא‏ : every ten (breadths) is a different domain
See the entire entry for rəšū, rəšūṯā n.f. control

BT Ber 25b(47) :שפיר קא עבדת‏ :
See the entire entry for šappīr adv. right, well