Narrated Abu Huraira: The Prophet (ﷺ) said, "The Hour will not be established till my followers copy the deeds of the previous nations and follow them very closely, span by span, and cubit by cubit (i.e., inch by inch)." It was said, "O Allah's Messenger! Do you mean by those (nations) the Persians and the Byzantines?" The Prophet said, "Who can it be other than they?"
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا ابْنُ أَبِي ذِئْبٍ، عَنِ الْمَقْبُرِيِّ، عَنْ أَبِي هُرَيْرَةَ، رضى الله عنه عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ تَقُومُ السَّاعَةُ حَتَّى تَأْخُذَ أُمَّتِي بِأَخْذِ الْقُرُونِ قَبْلَهَا، شِبْرًا بِشِبْرٍ وَذِرَاعًا بِذِرَاعٍ ". فَقِيلَ يَا رَسُولَ اللَّهِ كَفَارِسَ وَالرُّومِ. فَقَالَ " وَمَنِ النَّاسُ إِلاَّ أُولَئِكَ ".
sunnah.com