Ibn Ezra (Shemos 23:25) Man’s body comes from the lowest world. However, man’s soul, which is tied to the body, comes from on high. There are two powers that are intermediate between the body and the soul. These two powers are referred to in the main in Hebrew as ru’ach and nefesh, for the soul is the rational part of man and its place is in the brain of man. From it comes the power of all emotions and the desire to move. The ru’ach is situated in the heart. Life depends on the ru’ach. The ru’ach desires to dominate; that is, it seeks to overcome all opposition. It is the source of anger. The seat of the nefesh is in the liver.
Ibn Ezra (Shemos 31:03) Wisdom refers to the type of intelligence that is stored in the back of the brain. The word tevunah and also the word binah are related to the word ben (between). They refer to the intellectual faculty that lies in the middle cavity of the brain between knowledge and wisdom. For wisdom is situated in the posterior cavity of the brain, and knowledge, which is gathered by the senses, is located in the cavities of the brain that are adjacent to the forehead. Knowledge is called al takyil in Arabic. Understanding is called al fakrah and wisdom al hakhmah. Now Bezalel was endowed with every wisdom. He mastered the science of mathematics, geometry, proportions, astronomy, biology, and the secret of the human soul. He also towered over the people of his generation in that he knew all manner of workmanship. Many intelligent people do not possess even one practical skill. Hence Scripture prefixes a vav to the word kol (and) and reads, and in all manner of workmanship.