Musar for Sanhedrin 91:11
תניא ר"א בן יעקב אומר שמעתי שבית דין מכין ועונשין שלא מן התורה ולא לעבור על דברי תורה אלא כדי לעשות סייג לתורה
that the <i>Beth din</i> may, [whennecessary,] impose flagellation and pronounce [capital] sentences even wherenot [warranted] by the Torah; yet not with the intention of disregardingthe Torah but [on the contrary] in order to safeguardit.<span class="x" onmousemove="('comment',' Lit., 'to make a fence round it.' ');"><sup>21</sup></span> It once happened that a manrode a horse on the Sabbath in the Greek period and he was brought beforethe Court and stoned, not because he was liablethereto,<span class="x" onmousemove="('comment',' The prohibition against riding on the Sabbath is only a 'shebuth', l.e., a Rabbinical injunction. Cf. Bezah. 37a M. ');"><sup>22</sup></span>