“right hand.” In the biblical culture, the right hand was always more highly esteemed than the left hand. In fact, in some contexts the left hand was considered the hand of cursing. The reason the left hand came to be associated with evil or cursing was due to the fact that in the biblical culture people always washed themselves with their left hand after they went to the bathroom, which also meant that they only ate with their right hand. In some contexts, however, such as Proverbs 3:16, the “left hand” does not convey a sense of cursing, but rather it is simply less esteemed than the right hand. Also, because people used their right hand more than their left, the right hand and arm were usually stronger or more capable, so the “right hand” became associated with success and accomplishment while the left hand became associated with weakness and ineffectiveness.
It is also essential to know that although in our Western culture, the “heart” is associated with emotions and feelings, in the biblical culture it was associated with the mind and included thinking and planning. Ecclesiastes 10:2 is saying that the “heart” (i.e., the thinking, plans, attitudes, and actions) of the wise person leads him into blessings, while the heart of the fool leads him into trouble, into curses. Stripping the idioms away from the Hebrew text and giving the meaning of the verse yields something like the way the NET loosely translates the verse: “A wise person’s good sense protects him, but a fool’s lack of sense leaves him vulnerable.”