Sahih al-Bukhari, Volume 8, Book 76, Hadith 510 (USC-MSA) ⓘ
Narrated Sahl: Allah's Messenger said, "I have been sent and the Hour (is at hand) as these two," showing his two fingers and sticking (separating) them out.
حَدَّثَنَا سَعِيدُ بْنُ أَبِي مَرْيَمَ، حَدَّثَنَا أَبُو غَسَّانَ، حَدَّثَنَا أَبُو حَازِمٍ، عَنْ سَهْلٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " بُعِثْتُ أَنَا وَالسَّاعَةَ هَكَذَا " . وَيُشِيرُ بِإِصْبَعَيْهِ فَيَمُدُّ بِهِمَا.
also referenced under: Book 81, Hadith 92 (In-Book) & Hadith 6503 (DarusSalam)