When was the name "Jews" first used, and why is it mentioned in the Qur’an that Abraham was not a Jew?

The Jews were named "Jews" (Yahud) because of their saying and the saying of Moses, peace be upon him: "Indeed, we have repented (hudna) to You," meaning: we have turned to You in repentance, as mentioned by Ali and Ibn Mas'ud, may Allah be pleased with them both. As for the Christians, they were named "Christians" (Nasara) from the saying of Jesus, peace be upon him: "Be supporters (ansar) of Allah."