Good Manners and Form (Al-Adab)
حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنِ الْمَقْبُرِيِّ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " مَنْ لَمْ يَدَعْ قَوْلَ الزُّورِ وَالْعَمَلَ بِهِ وَالْجَهْلَ فَلَيْسَ لِلَّهِ حَاجَةٌ أَنْ يَدَعَ طَعَامَهُ وَشَرَابَهُ ". قَالَ أَحْمَدُ أَفْهَمَنِي رَجُلٌ إِسْنَادَهُ.Narrated Abu Huraira:The Prophet (ﷺ) said, "Whoever does not give up false statements (i.e. telling lies), and evil deeds, and speaking bad words to others, Allah is not in need of his (fasting) leaving his food and drink
From Sahih al-Bukhari, whose reports the scholars accept as authentic.