Muwatta Malik 1451

وَحَدَّثَنِي مَالِكٌ، أَنَّهُ سَمِعَ ابْنَ شِهَابٍ، يَقُولُ كَانَتْ ضَوَالُّ الإِبِلِ فِي زَمَانِ عُمَرَ بْنِ الْخَطَّابِ إِبِلاً مُؤَبَّلَةً تَنَاتَجُ لاَ يَمَسُّهَا أَحَدٌ حَتَّى إِذَا كَانَ زَمَانُ عُثْمَانَ بْنِ عَفَّانَ أَمَرَ بِتَعْرِيفِهَا ثُمَّ تُبَاعُ فَإِذَا جَاءَ صَاحِبُهَا أُعْطِيَ ثَمَنَهَا ‏.‏

Malik related to me that he heard Ibn Shihab say, "The stray camels in the time of Umar ibn al-Khattab were numerous and left alone. No one touched them until the time of Uthman ibn Affan. He ordered that they be publicised and then sold, and if the owner came afterwards, he was given their price

Reference

Muwatta Malik 1451

In-book

Book 36, Hadith 53