Board Thread:General Discussion/@comment-7644192-20140331215705/@comment-4975807-20140701205520

He obviously needed the real dagger with him in order to kill Zelena. If he gave it to Belle, it would look weird if he suddenly later asked for it back. If he did give the real one to her, he would never be get his revenge and Zelena would still be locked up in the prison and the time spell would have remained intact.