The Chariot

When the Buddha said that the five factors of personal experience were not the self and that the self was not found within them; He meant that on analysis, this name "I" did not correspond to any essence or entity. The Buddha has used the example of the chariot and the forest to explain the relation between the term "I" and the components of personal experience. The Buddha has explained that the term chariot, is simply a convenient name for a collection of parts that is assembled in a particular way. The wheels are not the chariot. Neither is the axle and neither is the carriage and so forth.Similarly, an individual tree is not a forest. Neither is a number of individual trees a forest. There is no forest apart from the individual trees. The term forest is just a convenient name for an assembly of individual trees. This is the thrust of the Buddha's rejection of the belief in a real, independent, permanent entity that is represented by the term "I". Such a permanent entity would have to be independent, would have to be sovereign in the way that a King is master of those around him. It would have to be permanent, immutable and impervious to change and such a permanent entity, such a self is nowhere to be found. The Buddha has applied the following analysis to the body and mind to indicate that the self is nowhere to be found either in the body or mind. The body is not the self. For if the body were the self, the self would be impermanent, would be subject to change, decay, destruction and death. So the body cannot be the self. The self does not possess the body, in the sense that I possess a cart or a television, because the self cannot control the body. The body falls ill, gets tired and old against our wishes. The body has a shape which often does not agree with our wishes. So in no way does the self possess the body. The self is not in the body. If we search our body from the top of our head to the tip of our toes, we can nowhere locate the self. The self is not in the bone, nor in the blood, nor in the marrow, nor in the hair, nor in the spittle. The self is nowhere to be found in the body. Similarly, the mind is not the self. The mind is subject to constant change. The mind is forever jumping like a monkey. The mind is happy at one moment and unhappy at the next. So the mind cannot be the self for the mind is constantly changing. The self does not possess the mind because the mind becomes excited and depressed against our wishes. Although we know certain thoughts are wholesome, and certain thoughts are unwholesome, the mind pursues unwholesome thoughts and is indifferent towards wholesome thoughts. So the self does not possess the mind because the mind acts independently of the self. The self is not in the mind. No matter how carefully we search the contents of our mind, no matter how carefully we search our thoughts, our feelings and ideas, we can nowhere find the self. There is a very simple exercise anyone of us can perform. We can all sit quietly for a brief period of time and look within our body and mind and without exception we will find that we cannot locate the self anywhere within the body nor the mind. The conclusion remains that the self is just a convenient name for a collection of factors. There is no self, no soul, no essence, no core of personal experience apart from the ever-changing, interdependent, impermanent physical and mental factors of personal experience such as our feelings, ideas, thoughts, habits and attitudes.
-Universal characteristics in Buddhism by J. P. Pathirana

Here the word 'self' refers to the individual ego self, not to the 'Universal Self' or Buddha Nature.

The Buddha did not deny the existence of the Universal Self.