وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ وَالَّذِي نَفْسِي بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ إِنَّمَا يَذَرُ شَهْوَتَهُ وَطَعَامَهُ وَشَرَابَهُ مِنْ أَجْلِي فَالصِّيَامُ لِي وَأَنَا أَجْزِي بِهِ كُلُّ حَسَنَةٍ بِعَشْرِ أَمْثَالِهَا إِلَى سَبْعِمِائَةِ ضِعْفٍ إِلاَّ الصِّيَامَ فَهُوَ لِي وَأَنَا أَجْزِي بِهِ ‏"‏ ‏.‏

Yahya related to me from Malik from Abu'z Zinad from al-Araj fromAbu Hurayra that the Messenger of Allah, may Allah bless him and granthim peace, said, "By the One in Whose hand my self is, the smell ofthe breath of a man fasting is better with Allah than the scent ofmusk.' He leaves his desires and his food and drink for My sake.Fasting is for Me and I reward it. Every good action is rewarded byten times its kind, up to seven hundred times, except fasting, whichis for Me, and I reward it.' " Translation Not Available

Book Ref: Muwatta Imam Malik Book 18 Hadith 691
Web Ref:  Muwatta Imam Malik Book 18 Hadith 58