Bar Kappara taught that whoever calls Abraham "Abram" violates a positive command. Rabbi Levi said that such a person violates both a positive and a negative command, as Genesis says: "Neither shall your name any more be called Abram" — that is a negative command — and also says: "But your name shall be called Abraham" — that is a positive command. The Midrash asked by analogy, if one calls Israel "Jacob" does one infringe a positive command? The Midrash answered that one does not, for it was taught that it was not intended that the name of Jacob should disappear, but that "Israel" should be his principal name and "Jacob" be his secondary name. Rabbi Zechariah interpreted it in Rabbi Aha's name as follows: In any event (in the words of ), "Your name is Jacob," except that, "But Israel shall be your name." Thus Jacob would be his principal name and "Israel" was added to it.