(14) باب قَوْلِ النَّبِيِّ صلى الله عليه وسلم " لَتَتْبَعُنَّ سَنَنَ مَنْ كَانَ قَبْلَكُمْ "
Narrated Abu Sa`id Al-Khudri:
The Prophet (ﷺ) said, "You will follow the ways of those nations who were before you, span by span and cubit by cubit (i.e., inch by inch) so much so that even if they entered a hole of a mastigure, you would follow them." We said, "O Allah's Messenger (ﷺ)! (Do you mean) the Jews and the Christians?" He said, "Whom else?"
Reference: Sahih al-Bukhari 7320
In-book reference: Book 96, Hadith 50
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 92, Hadith 422