Sahih Bukhari Volume 7, Book 68, Hadith 5303

حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، قَالَ أَبُو حَازِمٍ سَمِعْتُهُ مِنْ، سَهْلِ بْنِ سَعْدٍ السَّاعِدِيِّ صَاحِبِ رَسُولِ اللَّهِ صلى الله عليه وسلم يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ بُعِثْتُ أَنَا وَالسَّاعَةَ كَهَذِهِ مِنْ هَذِهِ أَوْ كَهَاتَيْنِ ‏"‏‏.‏ وَقَرَنَ بَيْنَ السَّبَّابَةِ وَالْوُسْطَى

Narrated By Sahl bin Sad As-Sa'idi : (A companion of Allah's Apostle) Allah's Apostle, holding out his middle and index fingers, said, "My advent and the Hour's are like this (or like these)," namely, the period between his era and the Hour is like the distance between those two fingers, i.e., very short.