Sunan an-Nasa'i, Book 22, Hadith 132 (In-Book) ⓘ
It was narrated that Raja bin Haiwah said: "Abu Umamah Al-Bahili narrated to me: 'I said: O Messenger of Allah, tell me of something by which Allah will benefic me. He said: Take to fasting, for there is nothing like it."'
أَخْبَرَنَا الرَّبِيعُ بْنُ سُلَيْمَانَ، قَالَ أَنْبَأَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي جَرِيرُ بْنُ حَازِمٍ، أَنَّ مُحَمَّدَ بْنَ عَبْدِ اللَّهِ بْنِ أَبِي يَعْقُوبَ الضَّبِّيَّ، حَدَّثَهُ عَنْ رَجَاءِ بْنِ حَيْوَةَ، قَالَ حَدَّثَنَا أَبُو أُمَامَةَ الْبَاهِلِيُّ، قَالَ قُلْتُ يَا رَسُولَ اللَّهِ مُرْنِي بِأَمْرٍ يَنْفَعُنِي اللَّهُ بِهِ . قَالَ " عَلَيْكَ بِالصِّيَامِ فَإِنَّهُ لاَ مِثْلَ لَهُ " .
also referenced under: Hadith 2221 (Reference) & Volume 3, Book 22, Hadith 2223 (DarusSalam)