The Prophet ﷺ said, "Whoever does not give up forged speech and evil actions, Allah is not in need of his leaving his food and drink (i.e. Allah will not accept his fasting.)" (Using translation from Bukhārī 1903)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «مَنْ لَمْ يَدَعْ قَوْلَ الزُّورِ وَالْعَمَلَ بِهِ وَالْجَهْلَ فِي الصَّوْمِ فَلَيْسَ لِلَّهِ حَاجَةٌ بِأَنْ يَدَعَ طَعَامَهُ وَلَا شَرَابَهُ»