‏البيوع : Hadeeth No:3654 Jabir b. Abdullah (Allaah be pleased with them) is reported to have said that Allaah's Messenger (sallAllaahu alayhi wa sallam) forbade the sale of a heap of dates the weight of which is unknown in accordance with the known weight of dates....

‏الإمارة : Hadeeth No:4608 It has been narrated on the authority of Abdullah b. Umar that the Messenger of Allaah (sallAllaahu alayhi wa sallam) used to forbid that one should travel to the land of the enemy taking the Qur'an (with him) lest it should fall into the hands of the enemy....