Quran 9:124~127 (Ayah at-Taubah)

Whenever a sûrah is revealed, some of them ask ˹mockingly˺, “Which of you has this increased in faith?” As for the believers, it has increased them in faith and they rejoice.But as for those with sickness in their hearts, it has increased them only in wickedness upon their wickedness, and they die as disbelievers. Do they not see that they are tried once or twice every year? Yet they neither repent nor do they learn a lesson.Whenever a sûrah is revealed, they look at one another, ˹saying,˺ “Is anyone watching you?” Then they slip away. ˹It is˺ Allah ˹Who˺ has turned their hearts away because they are a people who do not comprehend.Quran: 9:124~127Surah at-Taubah (Repentance)

The name of the surah, at-Taubah is derived from ت و ب and it occurs 87 times in the Quran. Interestingly, this surah has the highest usage of the words derived from ت و ب compared to all other surahs – it is used 17 times.
In Ayat 118, occurs the case of the three companions whom Allah turned to and accepted their tawbah to Him – those who had abstained from joining the Jihad at the Battle of Tabuk.

وَإِذَا مَاۤ أُنزِلَتۡ سُورَةࣱ فَمِنۡهُم مَّن یَقُولُ أَیُّكُمۡ زَادَتۡهُ هَـٰذِهِۦۤ إِیمَـٰنࣰاۚ فَأَمَّا ٱلَّذِینَ ءَامَنُوا۟ فَزَادَتۡهُمۡ إِیمَـٰنࣰا وَهُمۡ یَسۡتَبۡشِرُونَ

وَأَمَّا ٱلَّذِینَ فِی قُلُوبِهِم مَّرَضࣱ فَزَادَتۡهُمۡ رِجۡسًا إِلَىٰ رِجۡسِهِمۡ وَمَاتُوا۟ وَهُمۡ كَـٰفِرُونَ

أَوَ لَا یَرَوۡنَ أَنَّهُمۡ یُفۡتَنُونَ فِی كُلِّ عَامࣲ مَّرَّةً أَوۡ مَرَّتَیۡنِ
ثُمَّ لَا یَتُوبُونَ وَلَا هُمۡ یَذَّكَّرُونَ

وَإِذَا مَاۤ أُنزِلَتۡ سُورَةࣱ نَّظَرَ بَعۡضُهُمۡ إِلَىٰ بَعۡضٍ هَلۡ یَرَىٰكُم مِّنۡ أَحَدࣲ ثُمَّ ٱنصَرَفُوا۟ۚ صَرَفَ ٱللَّهُ قُلُوبَهُم بِأَنَّهُمۡ قَوۡمࣱ لَّا یَفۡقَهُونَ

This is the only Sūrah of the Qur’ān to which ‘In the Name of God, Most Gracious Most Merciful’ is not prefixed. Though the commentators have given different reasons for this, the correct one that which has been given by Imām Razi: namely this is because the Prophet himself did not dictate it at the beginning of the Sūrah. Therefore the Companions did not prefix it and their successors followed them. This is a further proof of the fact that utmost care has been taken to keep the Qur’ān intact so that it should remain in its complete and original form.

جب کوئی نئی سورت نازل ہوتی ہے تو ان میں سے بعض لوگ (مذاق کے طور پر مسلمانوں سے) پوچھتے ہیں کہ "کہو، تم میں سے کس کے ایمان میں اس سے اضافہ ہوا؟" (اس کا جواب یہ ہے کہ) جو لوگ ایمان لائے ہیں ان کے ایمان میں تو فی الواقع (ہر نازل ہونے والی سورت نے) اضافہ ہی کیا ہے اور وہ اس سے دلشاد ہیں
البتہ جن لوگوں کے دلوں کو (نفاق کا) روگ لگا ہوا تھا اُن کی سابق نجاست پر (ہر نئی سورت نے) ایک اور نجاست کا اضافہ کر دیا اور وہ مرتے دم تک کفر ہی میں مبتلا رہے

کیا یہ لوگ دیکھتے نہیں کہ ہر سال ایک دو مرتبہ یہ آزمائش میں ڈالے جاتے ہیں؟
مگر اِس پر بھی نہ توبہ کرتے ہیں
نہ کوئی سبق لیتے ہیں
جب کوئی سورت نازل ہوتی ہے تو یہ لوگ آنکھوں ہی آنکھوں میں ایک دوسرے سے باتیں کرتے ہیں کہ کہیں کوئی تم کو دیکھ تو نہیں رہا ہے، پھر چپکے سے نکل بھاگتے ہیں اللہ نے ان کے دل پھیر دیے ہیں
کیونکہ یہ ناسمجھ لوگ ہیں

The basic subjects of the Surah are: The non-believers who broke their treaties, Muslims have no obligation to honor treaties with them. Muslims must protect themselves from hypocrisy, weak faith and negligence. Battle of Tabuk and its lessons.
Sections:
Proclamation that the Treaty of Hudaibiyah is cancelled.
Honor the treaties with those who honor them. Fight with those who have broken the treaty.
Mushrikin are forbidden to be the caretakers of the Masjid al-Haram.
Muslims should trust Allah, not just their numbers.
Jews and Christians also committed Shirk. Command to spend in the path of Allah. The correct number of months.
The Tabuk expedition.
Those who stayed behind and did not participate in the Battle of Tabuk, hypocrites and weak in faith.
The proper distribution of charity. Those who speak ill of the Prophet or make fun of Allah and His Book.
The hypocrite men and women.