It is narrated from Nafi‘ that it is reported from Ibn ‘Umar (may Allah be pleased with him) that he did not see any harm in a person selling something for a fixed period of time, even though he did not possess its original at that time.
Hadith Referenceمسند الإمام الشافعي / كتاب البيوع / 1441
Hadith Takhrijاسناده ضعيف، لضعف شیخ الشافعي، اخرجه البيهقي: 6 /20 - وفى المعرفة السنن والآثار له (3571) ۔ و ابن ابي شيبة (20474)۔