وَقَالَتِ الْيَهُودُ عُزَيْرٌ ابْنُ اللَّهِ وَقَالَتِ النَّصَارَى الْمَسِيحُ ابْنُ اللَّهِ ۖ ذَٰلِكَ قَوْلُهُم بِأَفْوَاهِهِمْ ۖ يُضَاهِئُونَ قَوْلَ الَّذِينَ كَفَرُوا مِن قَبْلُ ۚ قَاتَلَهُمُ اللَّهُ ۚ أَنَّىٰ يُؤْفَكُونَ (30)
(9:30) The Jews say, "Ezra (`Uzairis the son of Allah,' *29 and the Christians say, "The Messiah is the son of God." Such are the baseless things they utter with their tongues, following in the footsteps of the former unbelievers. *30 May Allah afflict them with chastisement! Wherefrom are they being perverted?
*29) Uzair (Ezra) lived during the period around 450 B.C. The Jews regarded him with great reverence as the revivalist of their Scriptures which had beat lost during their captivity in Babylon aftar the death of Prophet Solomon. So much so that they had lost all the knowledge of their Law, their traditions and of Hebrew, their national language. Then it was Ezra who re-wrote the Old Testament and revived the Law. That is why they used very exaggerated language in his reverence which misled some of the Jewish sects to make him 'the son of God'. The Qur'an, however, does not assert that all the Jews were unanimous in declaring Ezra as 'the son of God'. What it intends to say is that the perversion in the articles of faith of the Jews concerning AIIah had degenerated to such an extent that there were some amongst them who considered Ezra as the son of God.
*30) "Those who were involved in Kufr before them" were the Egyptians, the Greeks, the Romans, the Persians, etc. The Jews and the Christians were so influenced by their philosophies, their superstitions and fancies that they also invented erroneous creeds like theirs. (For details sec E.N. 101 of Al-Ma Idah).