Regret

Al-Mā’idah 5:31

فَبَعَثَ ٱللَّهُ غُرَابٗا يَبۡحَثُ فِي ٱلۡأَرۡضِ لِيُرِيَهُۥ كَيۡفَ يُوَٰرِي سَوۡءَةَ أَخِيهِۚ قَالَ يَٰوَيۡلَتَىٰٓ أَعَجَزۡتُ أَنۡ أَكُونَ مِثۡلَ هَٰذَا ٱلۡغُرَابِ فَأُوَٰرِيَ سَوۡءَةَ أَخِيۖ فَأَصۡبَحَ مِنَ ٱلنَّٰدِمِينَ ٣١

Then Allah sent a crow searching in the ground to show him how to hide the disgrace of his brother. He said, "O woe to me! Have I failed to be like this crow and hide the body of my brother?" And he became of the regretful.

Al-Mā’idah 5:52

فَتَرَى ٱلَّذِينَ فِي قُلُوبِهِم مَّرَضٞ يُسَٰرِعُونَ فِيهِمۡ يَقُولُونَ نَخۡشَىٰٓ أَن تُصِيبَنَا دَآئِرَةٞۚ فَعَسَى ٱللَّهُ أَن يَأۡتِيَ بِٱلۡفَتۡحِ أَوۡ أَمۡرٖ مِّنۡ عِندِهِۦ فَيُصۡبِحُواْ عَلَىٰ مَآ أَسَرُّواْ فِيٓ أَنفُسِهِمۡ نَٰدِمِينَ ٥٢

So you see those in whose hearts is disease hastening into [association with] them, saying, "We are afraid a misfortune may strike us." But perhaps Allah will bring conquest or a decision from Him, and they will become, over what they have been concealing within themselves, regretful.

Al-Anfāl 8:36

إِنَّ ٱلَّذِينَ كَفَرُواْ يُنفِقُونَ أَمۡوَٰلَهُمۡ لِيَصُدُّواْ عَن سَبِيلِ ٱللَّهِۚ فَسَيُنفِقُونَهَا ثُمَّ تَكُونُ عَلَيۡهِمۡ حَسۡرَةٗ ثُمَّ يُغۡلَبُونَۗ وَٱلَّذِينَ كَفَرُوٓاْ إِلَىٰ جَهَنَّمَ يُحۡشَرُونَ ٣٦

Indeed, those who disbelieve spend their wealth to avert [people] from the way of Allah. So they will spend it; then it will be for them a [source of] regret; then they will be overcome. And those who have disbelieved - unto Hell they will be gathered.

Yūnus 10:54

وَلَوۡ أَنَّ لِكُلِّ نَفۡسٖ ظَلَمَتۡ مَا فِي ٱلۡأَرۡضِ لَٱفۡتَدَتۡ بِهِۦۗ وَأَسَرُّواْ ٱلنَّدَامَةَ لَمَّا رَأَوُاْ ٱلۡعَذَابَۖ وَقُضِيَ بَيۡنَهُم بِٱلۡقِسۡطِ وَهُمۡ لَا يُظۡلَمُونَ ٥٤

And if each soul that wronged had everything on earth, it would offer it in ransom. And they will confide regret when they see the punishment; and they will be judged in justice, and they will not be wronged

Al-Mu’minūn 23:40

قَالَ عَمَّا قَلِيلٖ لَّيُصۡبِحُنَّ نَٰدِمِينَ ٤٠

[Allah] said, "After a little, they will surely become regretful."

Ash-Shu‘arā’ 26:157

فَعَقَرُوهَا فَأَصۡبَحُواْ نَٰدِمِينَ ١٥٧

But they hamstrung her and so became regretful.

Saba’ 34:33

وَقَالَ ٱلَّذِينَ ٱسۡتُضۡعِفُواْ لِلَّذِينَ ٱسۡتَكۡبَرُواْ بَلۡ مَكۡرُ ٱلَّيۡلِ وَٱلنَّهَارِ إِذۡ تَأۡمُرُونَنَآ أَن نَّكۡفُرَ بِٱللَّهِ وَنَجۡعَلَ لَهُۥٓ أَندَادٗاۚ وَأَسَرُّواْ ٱلنَّدَامَةَ لَمَّا رَأَوُاْ ٱلۡعَذَابَۚ وَجَعَلۡنَا ٱلۡأَغۡلَٰلَ فِيٓ أَعۡنَاقِ ٱلَّذِينَ كَفَرُواْۖ هَلۡ يُجۡزَوۡنَ إِلَّا مَا كَانُواْ يَعۡمَلُونَ ٣٣

Those who were oppressed will say to those who were arrogant, "Rather, [it was your] conspiracy of night and day when you were ordering us to disbelieve in Allah and attribute to Him equals." But they will [all] confide regret when they see the punishment; and We will put shackles on the necks of those who disbelieved. Will they be recompensed except for what they used to do?

Al-Ḥujurāt 49:6

يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓاْ إِن جَآءَكُمۡ فَاسِقُۢ بِنَبَإٖ فَتَبَيَّنُوٓاْ أَن تُصِيبُواْ قَوۡمَۢا بِجَهَٰلَةٖ فَتُصۡبِحُواْ عَلَىٰ مَا فَعَلۡتُمۡ نَٰدِمِينَ ٦

O you who have believed, if there comes to you a disobedient one with information, investigate, lest you harm a people out of ignorance and become, over what you have done, regretful.