Hadith 517630
Chapter 54: General Subjects - كتاب الاستئذان
وَحَدَّثَنِي مَالِكٌ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَا مِنْ نَبِيِّ إِلاَّ قَدْ رَعَى غَنَمًا " . قِيلَ وَأَنْتَ يَا رَسُولَ اللَّهِ قَالَ " وَأَنَا " .
Malik related to me that he had heard that the Messenger of Allah, may Allah bless him and grant him peace, said, "There is no Prophet who has not herded sheep," and someone asked, "You as well, Messenger of Allah?" He said, "Myself as well."
Reference Muwatta Malik 517630
USC-MSA web (English) reference : Book 54, Hadith 18