What fasting is worth without the rest
It names three things and then dismisses the fast.
مَنْ لَمْ يَدَعْ قَوْلَ الزُّورِ وَالْعَمَلَ بِهِ وَالْجَهْلَ فَلَيْسَ لِلَّهِ حَاجَةٌ أَنْ يَدَعَ طَعَامَهُ وَشَرَابَهُ
Man lam yadaʿ qawla-z-zūri wa-l-ʿamala bihi wa-l-jahl, fa-laysa lillāhi ḥājatun an yadaʿa ṭaʿāmahu wa sharābah
Whoever does not give up false speech and acting on it, and ignorance, Allah has no need of his giving up his food and his drink.
The full narration
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
Source
Ṣaḥīḥ al-Bukhārī · 6057
Ṣaḥīḥ
- Agreed upon as authentic (al-Bukhārī / Muslim)