The root ن ص ح (n-ṣ-ḥ) in the Quran

وَقَاسَمَهُمَآ إِنِّى لَكُمَا لَمِنَ ٱلنَّٰصِحِينَ ۝٢١

And he swore [by Allāh] to them, "Indeed, I am to you from among the sincere advisors."

أُبَلِّغُكُمْ رِسَٰلَٰتِ رَبِّى وَأَنصَحُ لَكُمْ وَأَعْلَمُ مِنَ ٱللَّهِ مَا لَا تَعْلَمُونَ ۝٦٢

I convey to you the messages of my Lord and advise you; and I know from Allāh what you do not know.

أُبَلِّغُكُمْ رِسَٰلَٰتِ رَبِّى وَأَنَا۠ لَكُمْ نَاصِحٌ أَمِينٌ ۝٦٨

I convey to you the messages of my Lord, and I am to you a trustworthy adviser.

فَتَوَلَّىٰ عَنْهُمْ وَقَالَ يَٰقَوْمِ لَقَدْ أَبْلَغْتُكُمْ رِسَالَةَ رَبِّى وَنَصَحْتُ لَكُمْ وَلَٰكِن لَّا تُحِبُّونَ ٱلنَّٰصِحِينَ ۝٧٩

And he [i.e., Ṣāliḥ] turned away from them and said, "O my people, I had certainly conveyed to you the message of my Lord and advised you, but you do not like advisors."

فَتَوَلَّىٰ عَنْهُمْ وَقَالَ يَٰقَوْمِ لَقَدْ أَبْلَغْتُكُمْ رِسَٰلَٰتِ رَبِّى وَنَصَحْتُ لَكُمْ فَكَيْفَ ءَاسَىٰ عَلَىٰ قَوْمٍ كَٰفِرِينَ ۝٩٣

And he [i.e., Shuʿayb] turned away from them and said, "O my people, I had certainly conveyed to you the messages of my Lord and advised you, so how could I grieve for a disbelieving people?"

لَّيْسَ عَلَى ٱلضُّعَفَآءِ وَلَا عَلَى ٱلْمَرْضَىٰ وَلَا عَلَى ٱلَّذِينَ لَا يَجِدُونَ مَا يُنفِقُونَ حَرَجٌ إِذَا نَصَحُوا۟ لِلَّهِ وَرَسُولِهِۦ مَا عَلَى ٱلْمُحْسِنِينَ مِن سَبِيلٍ وَٱللَّهُ غَفُورٌ رَّحِيمٌ ۝٩١

There is not upon the weak or upon the ill or upon those who do not find anything to spend any discomfort [i.e., guilt] when they are sincere to Allāh and His Messenger. There is not upon the doers of good any cause [for blame]. And Allāh is Forgiving and Merciful.

وَلَا يَنفَعُكُمْ نُصْحِىٓ إِنْ أَرَدتُّ أَنْ أَنصَحَ لَكُمْ إِن كَانَ ٱللَّهُ يُرِيدُ أَن يُغْوِيَكُمْ هُوَ رَبُّكُمْ وَإِلَيْهِ تُرْجَعُونَ ۝٣٤

And my advice will not benefit you - although I wished to advise you - if Allāh should intend to put you in error. He is your Lord, and to Him you will be returned."

قَالُوا۟ يَٰٓأَبَانَا مَا لَكَ لَا تَأْمَ۫نَّا عَلَىٰ يُوسُفَ وَإِنَّا لَهُۥ لَنَٰصِحُونَ ۝١١

They said, "O our father, why do you not entrust us with Joseph while indeed, we are to him sincere counselors?

وَحَرَّمْنَا عَلَيْهِ ٱلْمَرَاضِعَ مِن قَبْلُ فَقَالَتْ هَلْ أَدُلُّكُمْ عَلَىٰٓ أَهْلِ بَيْتٍ يَكْفُلُونَهُۥ لَكُمْ وَهُمْ لَهُۥ نَٰصِحُونَ ۝١٢

And We had prevented from him [all] wet nurses before, so she said, "Shall I direct you to a household that will be responsible for him for you while they are to him [for his upbringing] sincere?"

وَجَآءَ رَجُلٌ مِّنْ أَقْصَا ٱلْمَدِينَةِ يَسْعَىٰ قَالَ يَٰمُوسَىٰٓ إِنَّ ٱلْمَلَأَ يَأْتَمِرُونَ بِكَ لِيَقْتُلُوكَ فَٱخْرُجْ إِنِّى لَكَ مِنَ ٱلنَّٰصِحِينَ ۝٢٠

And a man came from the farthest end of the city, running. He said, "O Moses, indeed the eminent ones are conferring over you [intending] to kill you, so leave [the city]; indeed, I am to you of the sincere advisors."

يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوا۟ تُوبُوٓا۟ إِلَى ٱللَّهِ تَوْبَةً نَّصُوحًا عَسَىٰ رَبُّكُمْ أَن يُكَفِّرَ عَنكُمْ سَيِّـَٔاتِكُمْ وَيُدْخِلَكُمْ جَنَّٰتٍ تَجْرِى مِن تَحْتِهَا ٱلْأَنْهَٰرُ يَوْمَ لَا يُخْزِى ٱللَّهُ ٱلنَّبِىَّ وَٱلَّذِينَ ءَامَنُوا۟ مَعَهُۥ نُورُهُمْ يَسْعَىٰ بَيْنَ أَيْدِيهِمْ وَبِأَيْمَٰنِهِمْ يَقُولُونَ رَبَّنَآ أَتْمِمْ لَنَا نُورَنَا وَٱغْفِرْ لَنَآ إِنَّكَ عَلَىٰ كُلِّ شَىْءٍ قَدِيرٌ ۝٨

O you who have believed, repent to Allāh with sincere repentance. Perhaps your Lord will remove from you your misdeeds and admit you into gardens beneath which rivers flow [on] the Day when Allāh will not disgrace the Prophet and those who believed with him. Their light will proceed before them and on their right; they will say, "Our Lord, perfect for us our light and forgive us. Indeed, You are over all things competent."