The Qur’an, the Jews and Ezra as the Son of God

Why does the Quran tell us that the Jews claim Ezra (ʿUzayr) is the son of God (Quran 9:30), when Jews do not make this claim or anything approaching it? This is not a question that arose just recently during an interfaith panel. It’s not a new question at all. Even in the ninth century, the Zaydi Imam and renowned scholar al-Qāsim b Ibrāhīm al-Rassī (d. 860 CE), who had studied Jewish and Christian scriptures in Egypt and who had engaged in debates with priests and rabbis, said that he had never encountered a Jew who believed Ezra was the son of God. Nor was this a question that Muslims pondered at ease in the libraries of Baghdad or Cordoba.