﴿ يَٰٓأَهْلَ ٱلْكِتَٰبِ لِمَ تُحَآجُّونَ فِىٓ إِبْرَٰهِيمَ وَمَآ أُنزِلَتِ ٱلتَّوْرَىٰةُ وَٱلْإِنجِيلُ إِلَّا مِنۢ بَعْدِهِۦٓ ۚ أَفَلَا تَعْقِلُونَ ﴾

“O FOLLOWERS of earlier revelation! Why do you argue about Abraham, seeing that the Torah and the Gospel were not revealed till [long] after him? Will you not, then, use your reason?”

Then Allah mentions their dispute with the Prophet (pbuh) in that they said they are of those who have surrendered to Allah and follow the Religion of Abraham, claiming this to be in the Torah. So Allah said: (O People of the Scripture! Why will ye argue about Abraham, when the Torah and the Gospel were not revealed till after him?) after Abraham. (Have ye then no sense?) that it is not mentioned in them that Abraham was Jew or Christian.