Sahih al-Bukhari 7538
صحيح البخاري#7538SahihNarrated Abu Huraira: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)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 97:163