It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said on the day of the Conquest of Makkah: "This city is sacred; Allah Almighty has made it sacred. Killing in it was not lawful for anyone before me, and it was made lawful for me only for an hour; so it is sacred. Allah Almighty has made it sacred until the Day of Resurrection. Its game is not to be chased away, its thorns are not to be cut, and its lost property is not to be picked up except by one who announces it, and its trees are not to be uprooted." Sayyiduna Abbas (may Allah be pleased with him) said: Except idhkhir, for it is used in the roofs of houses. He (peace and blessings be upon him) said: "Idhkhir is permitted."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللقطة / 12118