Avoid suspicion, for suspicion is the gravest lie in talk and do not be inquisitive about one another and do not spy upon one another and do not feel envy with the other, and nurse no malice, and nurse no aversion and hostility against one another. And be fellow-brothers and servants of Allah. (Using translation from Muslim 2563a)   

أَنَّ رَسُولَ اللهِ ﷺ قَالَ إِيَّاكُمْ وَالظَّنَّ فَإِنَّ الظَّنَّ أَكْذَبُ الْحَدِيثِ وَلَا تَجَسَّسُوا وَلَا تَحَسَّسُوا وَلَا تَنَافَسُوا وَلَا تَحَاسَدُوا وَلَا تَبَاغَضُوا وَلَا تَدَابَرُوا وَكُونُوا عِبَادَ اللهِ إِخْوَانًا  

I heard the Messenger of Allah ﷺ say: If you search for the faults of the people, you will corrupt them, or will nearly corrupt them. AbudDarda' said: These are the words which Mu'awiyah himself from the Messenger of Allah ﷺ, and Allah benefited him by them. (Using translation from Abū Dāʾūd 4888)   

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ إِنَّكَ إِنِ اتَّبَعْتَ عَوْرَاتِ النَّاسِ أَوْ عَثَرَاتِ النَّاسِ أَفْسَدْتَهُمْ أَوْ كِدْتَ أَنْ تُفْسِدَهُمْ قَالَ يَقُولُ أَبُو الدَّرْدَاءِ كَلِمَةٌ سَمِعَهَا مُعَاوِيَةُ مِنْ رَسُولِ اللهِ ﷺ فَنَفَعَهُ اللهُ بِهَا  

The Prophet ﷺ said: When a ruler seeks to make imputations against the people, he corrupts them. (Using translation from Abū Dāʾūd 4889)   

عَنِ النَّبِيِّ ﷺ قَالَ إِنَّ الْأَمِيرَ إِذَا ابْتَغَى الرِّيبَةَ فِي النَّاسِ أَفْسَدَهُمْ  

[Machine] "Abdul Rahman, I see that we have done what Allah has forbidden, 'and do not spy' (Surah Al-Hujurat, verse 12). Indeed, we have spied on them, so Umar withdrew from them and left them."  

عَبْدُ الرَّحْمَنِ أَرَى قَدْ أَتَيْنَا مَا نَهَى الله عَنْهُ {وَلَا تَجَسَّسُوا} [الحجرات 12] فَقَدْ تَجَسَّسْنَا فَانْصَرَفَ عَنْهُمْ عُمَرُ ؓ وَتَرَكَهُمْ  

[Machine] It was said to Abdullah, "Do you have any wine dripping from the beard of so-and-so?" He replied, "Indeed, Allah has forbidden us from spying, but if it becomes apparent to us, then we will take action."  

قِيلَ لِعَبْدِ اللهِ هَلْ لَكَ فِي فُلَانٍ تَقْطُرُ لِحْيَتُهُ خَمْرًا؟ فَقَالَ إِنَّ اللهَ قَدْ نَهَانَا أَنْ نَتَجَسَّسَ فَإِنْ يَظْهَرْ لَنَا نَأْخُذْهُ