كتاب الحج
15  
The Book of Pilgrimage
(82)
Chapter: The sanctity of Makkah and the sanctity of its game, grasses, trees and lost property, except for the one who announces it, is forever
(82)
باب تَحْرِيمِ مَكَّةَ وَصَيْدِهَا وَخَلاَهَا وَشَجَرِهَا وَلُقَطَتِهَا إِلاَّ لِمُنْشِدٍ عَلَى الدَّوَام
Sahih Muslim 1353 b

A hadith like this has been narrated on the authority of Mansur, but he did not mention:

" On that very day He created the heavens and the earth," and he (the narrator) substituted the word" fighting" (qital) for" killing" (qatl), and further said:" No one is to pick up the dropped thing except one who makes a public announcement of it."
وَحَدَّثَنِي مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا يَحْيَى بْنُ آدَمَ، حَدَّثَنَا مُفَضَّلٌ، عَنْ مَنْصُورٍ، فِي هَذَا الإِسْنَادِ بِمِثْلِهِ وَلَمْ يَذْكُرْ ‏"‏ يَوْمَ خَلَقَ السَّمَوَاتِ وَالأَرْضَ ‏"‏ ‏.‏ وَقَالَ بَدَلَ الْقِتَالِ ‏"‏ الْقَتْلَ ‏"‏ ‏.‏ وَقَالَ ‏"‏ لاَ يَلْتَقِطُ لُقَطَتَهُ إِلاَّ مَنْ عَرَّفَهَا ‏"‏ ‏.‏
Reference : Sahih Muslim 1353b
In-book reference : Book 15, Hadith 507
USC-MSA web (English) reference : Book 7, Hadith 3140
  (deprecated numbering scheme)