Hadithcore
Sahih Muslim, 1722 f
sahih

Zaid b. Khalid al-Juhani reported:

A person asked Allah's Messenger (ﷺ) about a lost camel; Rabi'a made this addition: He (the Prophet) was so much annoyed that his cheeks became red." The rest of the hadith is the same. He (the narrator) made this addition:" If its (that of the article) owner comes and he recognises the bag (which contained it) and its number, and the strap. then give that to them, but if not, then it is for you."

وَحَدَّثَنِي إِسْحَاقُ بْنُ مَنْصُورٍ، أَخْبَرَنَا حَبَّانُ بْنُ هِلاَلٍ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، حَدَّثَنِي يَحْيَى بْنُ سَعِيدٍ، وَرَبِيعَةُ الرَّأْىِ بْنُ أَبِي عَبْدِ الرَّحْمَنِ، عَنْ يَزِيدَ، مَوْلَى الْمُنْبَعِثِ عَنْ زَيْدِ بْنِ، خَالِدٍ الْجُهَنِيِّ أَنَّ رَجُلاً، سَأَلَ النَّبِيَّ صلى الله عليه وسلم عَنْ ضَالَّةِ الإِبِلِ ‏.‏ زَادَ رَبِيعَةُ فَغَضِبَ حَتَّى احْمَرَّتْ وَجْنَتَاهُ ‏.‏ وَاقْتَصَّ الْحَدِيثَ بِنَحْوِ حَدِيثِهِمْ وَزَادَ ‏

‏ فَإِنْ جَاءَ صَاحِبُهَا فَعَرَفَ عِفَاصَهَا وَعَدَدَهَا وَوِكَاءَهَا فَأَعْطِهَا إِيَّاهُ وَإِلاَّ فَهْىَ لَكَ ‏

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References2 variants
In-Book Reference
Book 31, Hadith 6
USC-MSA web (English) reference
Book 18, Hadith 4277 (deprecated numbering scheme)