3:199
وَإِنَّ مِنْ أَهْلِ ٱلْكِتَٰبِ لَمَن يُؤْمِنُ بِٱللَّهِ وَمَآ أُنزِلَ إِلَيْكُمْ وَمَآ أُنزِلَ إِلَيْهِمْ خَٰشِعِينَ لِلَّهِ لَا يَشْتَرُونَ بِـَٔايَٰتِ ٱللَّهِ ثَمَنًۭا قَلِيلًا ۗ أُو۟لَٰٓئِكَ لَهُمْ أَجْرُهُمْ عِندَ رَبِّهِمْ ۗ إِنَّ ٱللَّهَ سَرِيعُ ٱلْحِسَابِ
And indeed, among the People of the Scripture are those who believe in Allah and what was revealed to you and what was revealed to them, [being] humbly submissive to Allah. They do not exchange the verses of Allah for a small price. Those will have their reward with their Lord. Indeed, Allah is swift in account.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
The Condition of Some of the People of the Scriptures and their Rewards
Allah states that some of the People of the Book truly believe in Him and in what was sent down to Muhammad ﷺ, along with believing in the previously revealed Books, and they are obedient to Him and humble themselves before Allah.
لاَ يَشْتَرُونَ بِـَايَـتِ اللَّهِ ثَمَناً قَلِيلاً
(They do not sell the verses of Allah for a small price) 3:199, for they do not hide what they know of the glad tidings about the description of Muhammad ﷺ , his Prophethood, and the description of his Ummah. Indeed, these are the best people among the People of the Book, whether they were Jews or Christians. Allah said in Surat Al-Qasas,
الَّذِينَ ءَاتَيْنَـهُمُ الْكِتَـبَ مِن قَبْلِهِ هُم بِهِ يُؤْمِنُونَ وَإِذَا يُتْلَى عَلَيْهِمْ قَالُواْ ءَامَنَّا بِهِ إِنَّهُ الْحَقُّ مِن رَّبِّنَآ إنَّا كُنَّا مِن قَبْلِهِيُؤْتُونَ أَجْرَهُم مَّرَّتَيْنِ بِمَا صَبَرُواْ
(Those to whom We gave the Scripture before it, they believe in it (the Qur'an). And when it is recited to them, they say: "We believe in it. Verily, it is the truth from our Lord. Indeed even before it we were Muslims. These will be given their reward twice over, because they are patient,) 28:52-54. Allah said,