The Truthful Ones from among the People of the Scriptures rejoice at what Allah has revealed to Muhammad
Allah said,
وَالَّذِينَ اتَيْنَاهُمُ الْكِتَابَ
Those to whom We have given the Book,
and they adhere by it,
يَفْرَحُونَ بِمَا أُنزِلَ إِلَيْكَ
rejoice at what has been revealed unto you,
i.e. the Qur'an, because they have evidence in their Books affirming the truth of the Qur'an and conveying the good news of its imminent revelation, just as Allah said in another Ayah,
الَّذِينَ اتَيْنَـهُمُ الْكِتَـبَ يَتْلُونَهُ حَقَّ تِلَوَتِهِ
Those to whom We gave the Book recite it as it should be recited. (2;121)
Allah said,
قُلْ امِنُواْ بِهِ أَوْ لَا تُوْمِنُواْ إِنَّ الَّذِينَ أُوتُواْ الْعِلْمَ مِن قَبْلِهِ إِذَا يُتْلَى عَلَيْهِمْ يَخِرُّونَ لِلَذْقَانِ سُجَّدًا
وَيَقُولُونَ سُبْحَانَ رَبِّنَا إِن كَانَ وَعْدُ رَبِّنَا لَمَفْعُولاً
Say;"Believe in it or do not believe (in it). Verily, those who were given knowledge before it, when it is recited to them, fall down on their chins (faces) in humble prostration."
And they say;"Glory be to our Lord! Truly, the promise of our Lord must be fulfilled." (17;107-108)
meaning, Allah's promise to us in our Books to send Muhammad is true. It is certain and will surely come to pass and be fulfilled, so all praise to our Lord, how truthful is His promise, all the thanks are due to Him,
وَيَخِرُّونَ لِلٌّذْقَانِ يَبْكُونَ وَيَزِيدُهُمْ خُشُوعًا
And they fall down on their faces weeping and it increases their humility. (17;109)
Allah said next,
وَمِنَ الَاحْزَابِ مَن يُنكِرُ بَعْضَهُ
but there are among the Ahzab (Confederates) those who reject a part thereof.
meaning, `There are those among the sects who disbelieve in some of what was revealed to you (O Muhammad).'
Mujahid said that,
وَمِنَ الَاحْزَابِ
(but there are among the Ahzab (Confederates),
refers to Jews and Christians,
مَن يُنكِرُ بَعْضَهُ
(those who reject a part thereof),
meaning, `They reject a part of the truth that came down to you - O Muhammad.'
Similar was reported from Qatadah and Abdur-Rahman bin Zayd bin Aslam.
Allah said in similar Ayat,
وَإِنَّ مِنْ أَهْلِ الْكِتَـبِ لَمَن يُوْمِنُ بِاللَّهِ
And there are, certainly, among the People of the Scripture, those who believe in Allah. (3;199)
Allah said next,
قُلْ إِنَّمَا أُمِرْتُ أَنْ أَعْبُدَ اللّهَ وَلا أُشْرِكَ بِهِ
Say;"I am commanded only to worship Allah and not to join partners with Him..."
meaning, `I (Muhammad) was sent with the religion of worshipping Allah alone without partners, just as the Messengers before me,
إِلَيْهِ أَدْعُو
To Him (alone) I call,
I call the people to His path,
وَإِلَيْهِ مَأبِ
and to Him is my return.
final destination and destiny.'
Allah said