Wahb bin Munabbih says that this is the hadith or issue which I asked from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both), and he informed me that the Noble Prophet (peace and blessings be upon him) used to say, "When you go to sleep at night, tie the mouth of the water-skins with a knot and close the doors properly, and cover the vessels of food and drink, because when Satan comes, if the door is not closed, he enters. And if he finds the water-skin untied, he drinks from it. And if he finds the door closed and the water-skin tied, he does not untie the rope nor open the closed door. And if any of you does not find anything to cover his vessel, then he should place a piece of wood across it."