Malik related to me from Nafi that a man found something and wentto Abdullah ibn Umar and said to him, "I have found something. What doyou think I should do about it?" Abdullah ibn Umar said to him,"Publicise it!" He said, "I have done so." He said, "Do it again." Hesaid, "I have done so." Abdullah said, "I do not order you to use it.If you wished, you could have left it."
USC-MSA web (English) reference: Book 36, Hadith 48
Arabic reference: Book 36, Hadith 1451