Musar for Sanhedrin 27:2
מה עשה יהודה בן בבא הלך וישב לו בין שני הרים גדולים ובין שתי עיירות גדולות ובין שני תחומי שבת בין אושא לשפרעם וסמך שם חמשה זקנים ואלו הן ר"מ ור' יהודה ור' שמעון ור' יוסי ור' אלעזר בן שמוע רב אויא מוסיף אף ר' נחמיה
decreed that whoever performed an ordination should be put to death, and whoever received ordination should he put to death, the city in which the ordination took place demolished, and the boundaries<span class="x" onmousemove="('comment',' Heb. [H] denotes the boundaries without the town, as far as which one may go on the Sabbath. That such was meant here is evident from the following passage, which states that Judah b. Baba chose a spot between two Sabbath boundary lines. ');"><sup>3</sup></span> wherein it had been performed, uprooted. What did R. Judah b. Baba do? He went and sat between two great mountains, [that lay] between two large cities; between the Sabbath boundaries of the cities of Usha and Shefaram<span class="x" onmousemove="('comment',' Two Galilean cities prominent in the second century as places of refuge for the Sanhedrin. His purpose was that no city or region should suffer. ');"><sup>4</sup></span>