It is narrated from the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her), that the Messenger of Allah (peace and blessings be upon him) said: "The smell of the fasting person's mouth is purer in the sight of Allah than the fragrance of musk."
No one narrated this hadith from Abu al-Aswad (may Allah have mercy on him) except Ibn Lahi'ah (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الباء / 3199
Hadith Takhrij«أخرجه النسائي فى «المجتبى» برقم: 2233 / 15، والنسائي فى «السنن الكبرى» برقم: 3245، وأحمد فى «مسنده» برقم: 26675، والطبراني فى «الأوسط» برقم: 4179، 4232»