Reference for Sanhedrin 219:7
רב אשי אמר ראוי ליצטרע כתיב הכא ביד משה לו וכתיב התם (שמות ד, ו) ויאמר ה' לו עוד הבא נא ידך בחיקך
for Rab said: He who is unyielding in a dispute violates a negative command, as it is written, And let him not be as Korah, and as his company.<span class="x" onmousemove="('comment',' Ibid. XVII, 5. ');"><sup>17</sup></span> R. Ashi said: He deserves to be smitten with leprosy: here it is written, [as the Lord said] to him by the hand of Moses,'<span class="x" onmousemove="('comment',' Ibid. ');"><sup>18</sup></span> whilst elsewhere, it is said, And the Lord said furthermore unto him, Put now thine hand into thy bosom. [… and when he took it out, behold, his hand was leprous as snow].<span class="x" onmousemove="('comment',' Ex. IV, 6; to which 'the hand of Moses' is taken to allude. ');"><sup>19</sup></span>