Sahih Muslim , Book 54, Hadith 173 (In-Book) ⓘ
Anas reported that a person asked Allah's Messenger as to when the Last Hour would come. He had in his presence a young boy of the Ansar who was called Muhammad. Allah's Messenger said: If this young boy lives, he may not grow very old till (he would see) the Last Hour coming to you.
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا يُونُسُ بْنُ مُحَمَّدٍ، عَنْ حَمَّادِ بْنِ سَلَمَةَ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، أَنَّ رَجُلاً، سَأَلَ رَسُولَ اللَّهِ صلى الله عليه وسلم مَتَى تَقُومُ السَّاعَةُ وَعِنْدَهُ غُلاَمٌ مِنَ الأَنْصَارِ يُقَالُ لَهُ مُحَمَّدٌ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنْ يَعِشْ هَذَا الْغُلاَمُ فَعَسَى أَنْ لاَ يُدْرِكَهُ الْهَرَمُ حَتَّى تَقُومَ السَّاعَةُ " .
also referenced under: Hadith 2953 (Reference) & Book 41, Hadith 7051 (USC-MSA)