Reference for Bava Batra 108:1

ושאינה מסויימת במצריה עד כמה אמר רב פפא כדאזיל תיירא דשורי והדר

And if it is not bounded all round, how much does he acquire [by one stroke of the spade]?<span class="x" onmousemove="('comment',' This is the explanation of Tosaf. According to Rashb. the translation should be: 'If it is not bounded all round, how much must he dig up?' In either case we must supply the words 'according to Rab'. ');">¹</span> R. Papa said: The length of a furrow made by a pair of oxen, there and back.<span class="x" onmousemove="('comment',' According to Tosaf. this was a fixed measure of length. ');">²</span>

Jastrow