"When the Prophet ﷺ came to Al-Madinah, they were the worst people in weights and measures. Then Allah, Glorious is He revealed: "Woe to the Mutaffifun (those who give less in measure and weight)",[1] and they were fair in weights and measures after that. (Using translation from Ibn Mājah 2223)   

لَمَّا قَدِمَ نَبِيُّ اللهِ ﷺ الْمَدِينَةَ فَكَانُوا مِنْ أَخْبَثِ النَّاسِ كَيْلًا فَأَنْزَلَ اللهُ ﷻ {وَيْلٌ لِلْمُطَفِّفِينَ} [المطففين 1] فَحَسَّنُوا الْكَيْلَ بَعْدَ ذَلِكَ  

The Messenger of Allah ﷺ said: Woe to him who tells things, speaking falsely, to make people laugh thereby. Woe to him! Woe to him!. (Using translation from Abū Dāʾūd 4990)  

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «وَيْلٌ لِلَّذِي يُحَدِّثُ فَيَكْذِبُ لِيُضْحِكَ بِهِ الْقَوْمَ وَيْلٌ لَهُ وَيْلٌ لَهُ»  

[Machine] "Narrated by the Prophet ﷺ, Abu Dawood reported to us, Ya'qub narrated to me, my father narrated to me, from Salih, from Nafi', that Abdullah said: The Messenger of Allah ﷺ said, 'On the Day when all of humanity will stand before the Lord of the worlds' [Al-Mutaffifin, 83:6], on the Day of Judgment, so much so that one of them cannot hear anything more than halfway through their eardrum on that Day. Abu Abdur-Rahman said that Abdullah did not mention 'On the Day of Judgment', and Ubaidullah said, 'until they stand', and Abu Dawood said, 'until he disappears'."  

عَنِ النَّبِيِّ ﷺ أَخْبَرَنَا أَبُو دَاوُدَ حَدَّثَنَا يَعْقُوبُ حَدَّثَنِي أَبِي عَنْ صَالِحٍ حَدَّثَنَا نَافِعٌ أَنَّ عَبْدَ اللهِ قَالَ قَالَ رَسُولُ اللهِ ﷺ {يَوْمَ يَقُومُ النَّاسُ لِرَبِّ الْعَالَمِينَ} [المطففين 6] يَوْمُ الْقِيَامَةِ حَتَّى يَغِيبَ أَحَدُهُمْ إِلَى أَنْصَافِ أُذُنَيْهِ فِي رَشْحِهِ يَوْمَ الْقِيَامَةِ قَالَ أَبُو عَبْدِ الرَّحْمَنِ لَمْ يَذْكُرُ عُبَيْدُ اللهِ يَوْمَ الْقِيَامَةِ وَقَالَ عُبَيْدُ اللهِ «حَتَّى يَقُومَ» وَقَالَ أَبُو دَاوُدَ «حَتَّى يَغِيبَ»  

The Prophet ﷺ said, "On the Day when all mankind will stand before the Lord of the Worlds, some of them will be enveloped in their sweat up to the middle of their ears." (Using translation from Bukhārī 4938)   

عَنِ النَّبِيِّ ﷺ فِي قَوْلِهِ {يَوْمَ يَقُومُ النَّاسُ لِرَبِّ الْعَالَمِينَ} [المطففين 6] قَالَ «يَقُومُ أَحَدُهُمْ فِي رَشْحِهِ إِلَى أَنْصَافِ أُذُنَيْهِ»  

the Messenger of Allah said: “Verily, when the slave (of Allah) commits a sin, a black spot appears on his heart. When he refrains from it, seeks forgiveness and repents, his heart is polished clean. But if he returns, it increases until it covers his entire heart. And that is the ‘Ran’ which Allah mentioned: ‘Nay, but on their hearts is the Ran which they used to earn.’” (Using translation from Tirmidhī 3334)   

عَنْ رَسُولِ اللهِ ﷺ قَالَ إِنَّ الْعَبْدَ إِذَا أَخْطَأَ خَطِيئَةً نُكِتَتْ فِي قَلْبِهِ نُكْتَةٌ فَإِنْ هُوَ نَزَعَ وَاسْتَغْفَرَ وَتَابَ صَقَلَتْ قَلْبَهُ وَإِنْ عَادَ زِيدَ فِيهَا حَتَّى تَعْلُوَ قَلْبَهُ فَهُوَ الرَّانُ الَّذِي ذَكَرَ اللهُ {كَلَّا بَلْ رَانَ عَلَى قُلُوبِهِمْ مَا كَانُوا يَكْسِبُونَ} [المطففين 14]