Surah At-Tawbah, verse 76

يَحْلِفُونَ بِٱللَّهِ مَا قَالُوا۟ وَلَقَدْ قَالُوا۟ كَلِمَةَ ٱلْكُفْرِ وَكَفَرُوا۟ بَعْدَ إِسْلَـٰمِهِمْ وَهَمُّوا۟ بِمَا لَمْ يَنَالُوا۟ ۚ وَمَا نَقَمُوٓا۟ إِلَّآ أَنْ أَغْنَىٰهُمُ ٱللَّهُ وَرَسُولُهُۥ مِن فَضْلِهِۦ ۚ فَإِن يَتُوبُوا۟ يَكُ خَيْرًۭا لَّهُمْ ۖ وَإِن يَتَوَلَّوْا۟ يُعَذِّبْهُمُ ٱللَّهُ عَذَابًا أَلِيمًۭا فِى ٱلدُّنْيَا وَٱلْـَٔاخِرَةِ ۚ وَمَا لَهُمْ فِى ٱلْأَرْضِ مِن وَلِىٍّۢ وَلَا نَصِيرٍۢ ﴿٧٤﴾

They swear by Allāh that they did not say [anything against the Prophet (ﷺ)] while they had said the word of disbelief and disbelieved after their [pretense of] Islām and planned that which they were not to attain. And they were not resentful except [for the fact] that Allāh and His Messenger had enriched them of His bounty. So if they repent, it is better for them; but if they turn away, Allāh will punish them with a painful punishment in this world and the Hereafter. And there will not be for them on earth any protector or helper.

۞ وَمِنْهُم مَّنْ عَـٰهَدَ ٱللَّهَ لَئِنْ ءَاتَىٰنَا مِن فَضْلِهِۦ لَنَصَّدَّقَنَّ وَلَنَكُونَنَّ مِنَ ٱلصَّـٰلِحِينَ ﴿٧٥﴾

And among them are those who made a covenant with Allāh, [saying], "If He should give us from His bounty, we will surely spend in charity, and we will surely be among the righteous."

فَأَعْقَبَهُمْ نِفَاقًۭا فِى قُلُوبِهِمْ إِلَىٰ يَوْمِ يَلْقَوْنَهُۥ بِمَآ أَخْلَفُوا۟ ٱللَّهَ مَا وَعَدُوهُ وَبِمَا كَانُوا۟ يَكْذِبُونَ ﴿٧٧﴾

So He penalized them with hypocrisy in their hearts until the Day they will meet Him - because they failed Allāh in what they promised Him and because they [habitually] used to lie.

أَلَمْ يَعْلَمُوٓا۟ أَنَّ ٱللَّهَ يَعْلَمُ سِرَّهُمْ وَنَجْوَىٰهُمْ وَأَنَّ ٱللَّهَ عَلَّـٰمُ ٱلْغُيُوبِ ﴿٧٨﴾

Did they not know that Allāh knows their secrets and their private conversations and that Allāh is the Knower of the unseen?