An-Nisaa • EN-ASBAB-AL-NUZUL-BY-AL-WAHIDI
﴿ يَٰٓأَهْلَ ٱلْكِتَٰبِ لَا تَغْلُوا۟ فِى دِينِكُمْ وَلَا تَقُولُوا۟ عَلَى ٱللَّهِ إِلَّا ٱلْحَقَّ ۚ إِنَّمَا ٱلْمَسِيحُ عِيسَى ٱبْنُ مَرْيَمَ رَسُولُ ٱللَّهِ وَكَلِمَتُهُۥٓ أَلْقَىٰهَآ إِلَىٰ مَرْيَمَ وَرُوحٌۭ مِّنْهُ ۖ فَـَٔامِنُوا۟ بِٱللَّهِ وَرُسُلِهِۦ ۖ وَلَا تَقُولُوا۟ ثَلَٰثَةٌ ۚ ٱنتَهُوا۟ خَيْرًۭا لَّكُمْ ۚ إِنَّمَا ٱللَّهُ إِلَٰهٌۭ وَٰحِدٌۭ ۖ سُبْحَٰنَهُۥٓ أَن يَكُونَ لَهُۥ وَلَدٌۭ ۘ لَّهُۥ مَا فِى ٱلسَّمَٰوَٰتِ وَمَا فِى ٱلْأَرْضِ ۗ وَكَفَىٰ بِٱللَّهِ وَكِيلًۭا ﴾
“O FOLLOWERS of the Gospel! Do not overstep the bounds [of truth] in your religious beliefs, and do not say of God anything but the truth. The Christ Jesus, son of Mary, was but God's Apostle - [the fulfilment of] His promise which He had conveyed unto Mary - and a soul created by Him. Believe, then, in God and His apostles, and do not say, "[God is] a trinity". Desist [from this assertion] for your own good. God is but One God; utterly remote is He, in His glory, from having a son: unto Him belongs all that is in the heavens and all that is on earth; and none is as worthy of trust as God.”
(O People of the Scripture! Do not exaggerate in your religion�) [4:171]. This was revealed about some Christian denominations who claimed that Jesus is the son of Allah, and so Allah, exalted is He, revealed (O People of the Scripture! Do not exaggerate in your religion nor utter aught concerning Allah save the truth�).