The Talmud of Babylonia, Bavli Shabbat Folio 31a (I.12, A.-C.; Neusner)

There was another case of gentile who came before Shammai. He said to him, "Convert me on the stipulation that you teach me the entire Torah while I am standing on one foot." He drove him off with the building cubit that he had in his hand. He came before Hillel: "Convert me." He said to him, "‘What is hateful to you, to your fellow don’t do.’ That’s the entirety of the Torah; everything else is elaboration. So go, study."