When I was dealing with the subject of general inflow and of inflow in particular into each human being, and the fact that every spirit and angel is a center of inflowings such that myriads of myriads stream into every mental image that a person on earth or a spirit thinks of as simple or single, then by lofty spiritual mental images it was granted to some who were capable of receiving them to understand that this is the case. Among them were both Mohammeds, who now say that they had grasped it so well that they had become thoroughly convinced that this is the case, and that no person on earth can ever grasp it who supposes an idea to be something simple, nor can any spirit. Hence they cannot grasp it as long as heaven is not open to the person or spirit so that such inner sight can be imparted to them.