You are reading a tafsir for the group of verses 29:46 to 29:47
وَلَا
تُجَادِلُوْۤا
اَهْلَ
الْكِتٰبِ
اِلَّا
بِالَّتِیْ
هِیَ
اَحْسَنُ ۖۗ
اِلَّا
الَّذِیْنَ
ظَلَمُوْا
مِنْهُمْ
وَقُوْلُوْۤا
اٰمَنَّا
بِالَّذِیْۤ
اُنْزِلَ
اِلَیْنَا
وَاُنْزِلَ
اِلَیْكُمْ
وَاِلٰهُنَا
وَاِلٰهُكُمْ
وَاحِدٌ
وَّنَحْنُ
لَهٗ
مُسْلِمُوْنَ
۟
وَكَذٰلِكَ
اَنْزَلْنَاۤ
اِلَیْكَ
الْكِتٰبَ ؕ
فَالَّذِیْنَ
اٰتَیْنٰهُمُ
الْكِتٰبَ
یُؤْمِنُوْنَ
بِهٖ ۚ
وَمِنْ
هٰۤؤُلَآءِ
مَنْ
یُّؤْمِنُ
بِهٖ ؕ
وَمَا
یَجْحَدُ
بِاٰیٰتِنَاۤ
اِلَّا
الْكٰفِرُوْنَ
۟
3

Commentary

وَلَا تُجَادِلُوا أَهْلَ الْكِتَابِ إِلَّا بِالَّتِي هِيَ أَحْسَنُ إِلَّا الَّذِينَ ظَلَمُوا (And do not debate with the people of the Book unless it is in the best way, except those from them who commit injustice. - 29:46). It means that if one has to get involved in a discussion or debate with the people of the book, he should present his arguments in an affable manner. For instance, it is prudent to answer an impudent remark with politeness, the rage with mildness, and uncivilized tumult with dignified speech.

إِلَّا الَّذِينَ ظَلَمُوا (except those from them who commit injustice - 29:46). But those who wronged you in that they stuck to their stubbornness and obstinacy in return to your dignified gentle speech, they do not deserve this kindness from you. If you give them tit for tat, you are justified, although it is still preferable that they are not replied with rudeness for rudeness, and cruelly for their cruelty. Rather they be treated with courtesy for their rudeness, and with fairness for their unfairness. Some other Qur'anic verses elaborate this advice: وَإِنْ عَاقَبْتُمْ فَعَاقِبُوا بِمِثْلِ مَا عُوقِبْتُم بِهِ وَلَئِن صَبَرْ‌تُمْ لَهُوَ خَيْرٌ‌ لِّلصَّابِرِ‌ينَ (16:126): That is, you are entitled to take revenge of their injustice in equal manner, 'but if you opt for patience, it is definitely much better for those who are patient'.

The advice given in this verse for a polite and dignified treatment in the case of a debate with the people of the book is also accorded in Surah An-Nahl with regard to the pagans. At this place the people of the book are especially identified for the reason given right after this. That is, if they were to ponder, there is a great deal common in the two faiths, which should help them accept Islam. Hence it is said وَقُولُوا آمَنَّا بِالَّذِي أُنزِلَ إِلَيْنَا وَأُنزِلَ إِلَيْكُمْ (And say: We believe in what is sent down to us and sent down to you - 29:46). It means that the Muslims should tell the people of the book at the time of argument ` we have faith in the revelations sent to us through our Prophet ﷺ ، and also on those revelations which were sent to you through your prophets. Hence, you have no reason for any hostility against us'.

Does this verse endorse the authenticity of Torah and Injil in their present form?

The manner in which this verse endorses the belief of Muslims in Torah and Injil is their general faith in them, as they were revealed in their original form. It means that whatever Allah Ta’ ala had revealed in these books, they had faith in that. It does not mean that they have faith in their altered and distorted form of the text as well. Many of the alterations were made in the books even before the time of the Holy Prophet ﷺ ، and many more were carried out later. This work on amendments has not ceased yet. Muslims have faith only on that part of Torah and Injil that were revealed on Sayyidna Musa (علیہ السلام) and Sayyidna Isa (علیہ السلام) respectively. The altered part of the books is excluded from that.

Torah and Injil in their present form can neither be believed nor rejected altogether

It is recorded in Sahih Al-Bukhari that Sayyidna Abu Hurairah ؓ has reported that the People of the Book used to read Torah and Injil in their original language, Hebrew, but for Muslims they would relate only its translation in Arabic. the Holy Prophet ﷺ instructed the Muslims in this regard that they should neither believe nor reject what they (Jews and Christians) tell them, and instead simply say آمَنَّا بِالَّذِي أُنزِلَ إِلَيْنَا وَأُنزِلَ إِلَيْكُمْ (We believe in what is sent down to us and sent down to you - 29:46). That is ` We have symbolic faith in that what was revealed on your prophets, but what you are telling us we do not consider it as authentic. Therefore, we abstain from endorsing or rejecting it'.