The Prophet ﷺ said, "A good deed is rewarded tenfold. Fasting is for Me, and I Myself reward it. He gives up his food and drink for My sake."Yazid said, "for My sake," meaning, "Fasting is for Me, and I Myself reward it. The breath of the fasting person is more fragrant to Allah than the scent of musk."
حدثنا محمد بن جعفر حدثنا هشام بن حسان القردوسي ويزيد بن هارون قال أخبرنا هشام عن محمد بن سيرين
عن النبي ﷺ قال الحسنة بعشر أمثالها والصوم لي وأنا أجزي به يذر طعامه وشرابه بجراي قال يزيد من أجلي الصوم لي وأنا أجزي به ولخلوف فم الصائم عند الله أطيب من ريح المسك
Both its chains of transmission are sahih. Ahmad narrated it from Muhammad bin Jafar Ghundar, and from Yazid bin Harun, both of them from Hisham bin Hassan.Al-Qaradusi, with a damma on the qaf, a sukun on the ra, a damma on the plain dal, and after the waw a plain sin, is a designation referring to the Qaradis, a clan of the Azd who settled in Basra, so the quarter was named after them, and Hisham bin Hassan was named after that quarter. See Al-Lubab by Ibn Athir, 2:252.This hadith has come down from Abu Hurairah through various routes and with many chains, both at length and abridged. Ahmad narrated it in the Musnad more than thirty times. Malik narrated it in Muwatta, p. 310, from Abu Zinad, from Araj, from Abu Hurairah. It will come again in the Musnad through Malik's route at 10000 and 10704. Bukhari narrated it, 4:87-91, through his route. Muslim narrated it, 1:316-317, with many chains. Part of its meaning has already appeared at 7174, from the combined hadith of Abu Hurairah and Abu Saeed. Something similar in meaning has already appeared at 4256, from the hadith of Ibn Masud, with a daif chain.From the beginning of his saying, "Fasting is for Me, and I reward for it," to its end, this is a hadith qudsi. It was not explicitly stated as such in this narration because it is obvious, and there is no room for confusion about it. Likewise it appears in Malik's narration. Hafiz said in Al-Fath, "He did not explicitly attribute it to Allah, since it was already known and there was no ambiguity in it." He then pointed to many of its narrations in which it is explicitly stated that Allah, Mighty and Majestic, says it.As for his saying "bi-jarra-i," with a fatha on the jim, a doubled ra, and after the alif a ya with a fatha, meaning "for my sake," as it appears in the narration of Yazid bin Harun, which Ahmad related in detail. It may also be read "jaraay," and it was recorded that way in K. In Al-Lisan, 5:199, it says, "I did that because of your misdeed (jariratika), and min jaraka and min jaraika mean for your sake." It also says, 5:200, "Sometimes they say min jaraka without doubling, and min jaraaka with elongation, from the weak-lettered root."