Yahya related to me from Malik from Nafi that when Abdullah ibnUmar gave something in the way of Allah, he would say to its owner,"When you reach Wadi'l-Qura, (on the outskirts of Madina) then it isyour affair." (ID)
USC-MSA web (English) reference: Book 21, Hadith 13 (ID)
Arabic reference (ID): Book 21, Hadith 974 (ID)