“Your name will no longer be called Abram, but your name will be Abraham; for I have made you the father of a multitude of nations” (Genesis 17:5). “Your name will no longer be called Abram, but your name will be Abraham” – bar Kappara said: Anyone who calls Abraham Abram violates a prohibition. Rabbi Levi said: [He violates] a positive commandment, and a prohibition: “Your name will no longer be called Abram” – a prohibition; “but your name will be Abraham” – a positive commandment.
But you see that the members of the Great Assembly called him Abram, as it is stated: “You are the Lord the God, who chose Abram, and took him out of Ur of the Chaldeans, and set his name as Abraham.” (Nehemiah 9:7)33The Sages at the beginning of the era of the building of the Second Temple were known as the Men of the Great Assembly, including Ezra, who is the speaker in this verse. That case is different, as [it means:] You chose him while he was still called Abram.
Similarly, does one who calls Sarah Sarai violate a positive commandment?34“God said to Abraham: Sarai your wife, you shall not call her name Sarai, as Sarah is her name” (Genesis 17:15). It was [only] he [Abraham] who was commanded regarding her. Similarly, does one who calls Israel Jacob violate a positive commandment? It is taught: [God’s intent was] not that the name Jacob should be uprooted from its place, but rather, “[Your name is Jacob]…rather, Israel shall be your name” (Genesis 35:10) – Israel is to be the primary name, and Jacob the secondary name.
Rabbi Zavda in the name of Rabbi Aḥa: In any case, “your name is Jacob…rather, Israel” – Jacob is the primary name, and Israel is in addition to it.