Hadith 1:153
Muttafaqun 'alayh (Zubair `Aliza'i)
He also reported God’s messenger as saying, “Faith will shrink back to Medina as a snake shrinks back to its hole.” (Bukhari and Muslim.)
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ الْإِيمَانَ لَيَأْرِزُ إِلَى الْمَدِينَةِ كَمَا تأرز الحيية إِلَى جحرها»
Original Reference: Mishkat al-Masabih 160