3:68
إِنَّ أَوْلَى ٱلنَّاسِ بِإِبْرَٰهِيمَ لَلَّذِينَ ٱتَّبَعُوهُ وَهَٰذَا ٱلنَّبِىُّ وَٱلَّذِينَ ءَامَنُوا۟ ۗ وَٱللَّهُ وَلِىُّ ٱلْمُؤْمِنِينَ
Indeed, the most worthy of Abraham among the people are those who followed him [in submission to Allah] and this prophet, and those who believe [in his message]. And Allah is the ally of the believers.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
Disputing with the Jews and Christians About the Religion of Ibrahim
Allah censures the Jews and Christians for their dispute with Muslims over Ibrahim Al-Khalil and the claim each group made that he was one of them. Muhammad bin Ishaq bin Yasar reported that Ibn `Abbas said, "The Christians of Najran and Jewish rabbis gathered before the Messenger of Allah ﷺ and disputed in front of him. The rabbis said, `Ibrahim was certainly Jewish.' The Christians said, `Certainly, Ibrahim was Christian.' So Allah sent down,
يأَهْلَ الْكِتَـبِ لِمَ تُحَآجُّونَ فِى إِبْرَهِيمَ
(O people of the Scripture (Jews and Christians)! Why do you dispute about Ibrahim,) meaning, `How is it that you, Jews, claim that Ibrahim was Jew, although he lived before Allah sent down the Tawrah to Musa How is it that you, Christians, claim that Ibrahim was Christian, although Christianity came after his time" This is why Allah said,
أَفَلاَ تَعْقِلُونَ
(Have you then no sense)