Sahih al-Bukhari, Book 78, Hadith 13 (In-Book) ⓘ
Narrated Abu Ayyub Al-Ansari: It was said" "O Allah's Messenger! Inform me of a deed which will make me enter Paradise." (continues through a different chain in the next hadith)
حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ، قَالَ أَخْبَرَنِي ابْنُ عُثْمَانَ، قَالَ سَمِعْتُ مُوسَى بْنَ طَلْحَةَ، عَنْ أَبِي أَيُّوبَ، قَالَ قِيلَ يَا رَسُولَ اللَّهِ، أَخْبِرْنِي بِعَمَلٍ، يُدْخِلُنِي الْجَنَّةَ.
also referenced under: Hadith 5982 (DarusSalam) & Volume 8, Book 73, Hadith 12 (USC-MSA)