Hadith 2082

Buraida said that once when Bilal went in to visit God’s messenger while he was having his morning meal he invited him to join him, and when Bilal replied that he was fasting, he said, “We are eating our provision and Bilal’s superior provision is in paradise. Did you know, Bilal, that the bones of one who fasts extol God and that the angels ask forgiveness for him as long as people eat beside him?” Baihaqi transmitted it in Shu'ab al-iman.

عَن بُرَيْدَة قَالَ: دَخَلَ بِلَالٌ عَلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ يَتَغَدَّى فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الْغَدَاءَ يَا بِلَالُ» . قَالَ: إِنِّي صَائِمٌ يَا رَسُولَ اللَّهِ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «نَأْكُلُ رِزْقَنَا وَفَضْلُ رِزْقِ بِلَالٍ فِي الْجَنَّةِ أشعرت يَا بِلَال أَن الصَّائِم نُسَبِّح عِظَامه وَتَسْتَغْفِر لَهُ الْمَلَائِكَةُ مَا أَكَلَ عِنْدَهُ؟» . رَوَاهُ الْبَيْهَقِيُّ فِي شعب الْإِيمَان

Reference: 5620820
In-book reference: Book 7, Hadith 2082
Hadith 2082 - Fasting - Mishkat al-Masabih - Sunnah.com