Muwatta Malik 1778

وَحَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَبْدِ اللَّهِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ أَبِي صَعْصَعَةَ، عَنْ أَبِيهِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّهُ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ يُوشِكُ أَنْ يَكُونَ خَيْرُ مَالِ الْمُسْلِمِ غَنَمًا يَتْبَعُ بِهَا شَعَفَ الْجِبَالِ وَمَوَاقِعَ الْقَطْرِ يَفِرُّ بِدِينِهِ مِنَ الْفِتَنِ ‏"‏ ‏.‏

Malik related to me from Abd ar-Rahman ibn Abd ar-Rahman ibn Sasaca from his father that Abu Said al-Khudri said that the Messenger of Allah, may Allah bless him and grant him peace, said, "It will soon happen that the best property of a muslim will be sheep which he takes to the peaks of the mountains and the valleys, fleeing with his deen from trials

Reference

Muwatta Malik 1778

In-book

Book 54, Hadith 16