Hisbonenus is essentially the idea of looking intensely into the depths of a topic and going over it a lot until one understands it clearly with all its parts in particular detail... For there are three things in every intellectual concept: the depth, length and width. The width is the aspect of the explanations of the concept to every side (from every angle) with many particular details as in the width of a river and not just the ideas as they are as in a narrow river. And the length is the immense lowering of the intellect to enclothe the concept in various allegories until it is brought down to the grasp of a little child etc. Like a river that flows and is drawn (down) its length.
And Now Chapter 1.04
The depth of a concept is like the depth of a river, that from there it widens out, but it itself is not wide at all. This depth (which is called the undercurrent) is the most essential part of the river for it is the main flow of water from its source. The essential defining factor that distinguishes a river from other bodies of water such as, for example, a lake, is the fact that it is a moving body of water, flowing from a mountain to the ocean. The usual way that a river is made up is that the water on the sides tend to be shallow and calm, while in the middle the water is deep and flows quickly, freed from the friction with the sides. This quick current is often unapparent from the surface and at times is so strong that it can be potentially dangerous to swimmers, at times sucking an unwary swimmer under with it or just carrying him quickly down stream. This hidden power is made apparent only when its flow is obstructed by something, giving rise to great rapids.
Similarly, the depth of an idea is the essential point of the idea, as it is essentially, transcending explanation or definition. This is also what is called the Omek Hamusag (depth of the understandable, or more literally the depth of what can be grasped.) This is when one understands an explanation so that they actually get the point of it, that which was not actually explained. It is from this inner point that everything spreads out from, forming the many explanations of one's understanding to all sides, with a great width, encompassing many details.
For example, when one learns how to add in school, the teacher gives a few examples on the board and shows, step by step, how they are solved. Then the teacher gives the students different problems for homework, ones that were not explained before. But how are the students supposed to solve them if they were never explained before? The answer is that after the students were explained a few examples they get the hang of how it’s done. This was the real point or depth of the explanations, so that they can add any problem, not just the ones they were given. So that once one knows how to add in the way of a point - in a way that ‘you just do it,’ then one can add any problem. Then one's understanding will automatically encompasses the width, of how to add all of the specific problems, as well. So too the length of an idea, with the intense descent of the idea to be en-clothed in examples and analogies. This too comes out of the original depth and was included within it. Like when a teacher teaches young children how to add, even beginning with 1 + 1 = 2 is too abstract and must be lowered into a more physical example, like one apple plus one apple is two apples. Now the inner theory of mathematics can really be applied to add anything and the knowledge of adding apples was included in the inner understanding of how to add and once one learns how to add then one can add anything.