An empty container makes a lot of noise (IM 411)

There is a beautiful quote by Plato which goes - "A wise man speaks because he has something to say, but a fool speaks because he want to say something." This is so relatable. This is same as saying an empty container makes a lot of noise. Those who have knowledge don't speak too much they just listen. A person without any knowledge just speak for the sake of speaking. A container full of water does not make a lot of noise.