The Repentance
فَإِن تَوَلَّوْا۟ فَقُلْ حَسْبِىَ ٱللَّهُ لَآ إِلَـٰهَ إِلَّا هُوَ ۖ عَلَيْهِ تَوَكَّلْتُ ۖ وَهُوَ رَبُّ ٱلْعَرْشِ ٱلْعَظِيمِ
But if they turn away, [O Muhammad], say, "Sufficient for me is Allah; there is no deity except Him. On Him I have relied, and He is the Lord of the Great Throne."
Nearby ayahs help place verse 9:129 in sequence and meaning.
وَإِذَا مَآ أُنزِلَتْ سُورَةٌۭ نَّظَرَ بَعْضُهُمْ إِلَىٰ بَعْضٍ هَلْ يَرَىٰكُم مِّنْ أَحَدٍۢ ثُمَّ ٱنصَرَفُوا۟ ۚ صَرَفَ ٱللَّهُ قُلُوبَهُم بِأَنَّهُمْ قَوْمٌۭ لَّا يَفْقَهُونَ
And whenever a surah is revealed, they look at each other, [saying], "Does anyone see you?" and then they dismiss themselves. Allah has dismissed their hearts because they are a people who do not understand.
لَقَدْ جَآءَكُمْ رَسُولٌۭ مِّنْ أَنفُسِكُمْ عَزِيزٌ عَلَيْهِ مَا عَنِتُّمْ حَرِيصٌ عَلَيْكُم بِٱلْمُؤْمِنِينَ رَءُوفٌۭ رَّحِيمٌۭ
There has certainly come to you a Messenger from among yourselves. Grievous to him is what you suffer; [he is] concerned over you and to the believers is kind and merciful.