The Prophet ﷺ said that your Lord said, "Every (sinful) deed can be expiated; and the fast is for Me, so I will give the reward for it; and the smell which comes out of the mouth of a fasting person, is better in Allah's Sight than the smell of musk." (See Hadith No. 584) (Using translation from Bukhārī 7538)
عَنِ النَّبِيِّ ﷺ يَرْوِيهِ عَنْ رَبِّكُمْ ﷻ كُلُّ الْعَمَلِ كَفَّارَةٌ وَالصَّوْمُ لِي وَأَنَا أَجْزِي بِهِ وَلَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللهِ مِنْ رِيحِ الْمِسْكِ