Midrash Tanchuma, Shoftim 5

(Deut. 16:18:) “You shall appoint [judges and law officers] for yourselves”; and not for the peoples of the world. Another interpretation (of Deut. 16:18), “You shall appoint [judges and law officers] for yourselves (literally, yourself)”: [This] teaches that the judges were called in the name of Moses. Moreover, this is one of three things over which Moses risked his life and were called by his name.<sup class="footnote-marker">13</sup><i class="footnote"><i>Mekhilta deRabbi Ishmael, Shirata,</i> 1 on Exod. 15:1; Exod. R. 30:4; Numb. R. 12:9.</i> He offered his life over the Torah, [as stated (in Exod. 34:28),] “And he was there with the Lord forty days and forty nights.” And it was called by his name, as stated (in Mal. 3:22), “Remember [the] Torah of My servant Moses.” He offered his life over Israel, as stated (in Exod. 32:32), “But now, if You will forgive their sin, [well and good; but if not, please blot me out].” And they were called by his name, as stated (in Exod. 32:7, in which the Holy One, blessed be He, tells Moses), “Go down, for your people have acted basely.” He also offered his life over the judges, as stated (in Exod. 2:12-14), “he smote the Egyptian [and hid him in the sand]. When he went out on the second day, [there were two Hebrew men fighting; so he said to the wicked one, ‘Why would you strike your comrade?’] But he said, ‘Who appointed you a prince and a judge?’” For that reason they were called in his name, as stated (in Deut. 33:21), “He chose for himself the best… he executed the Lord’s judgments, and His decisions for Israel.”