“…Know that intention (niyyah), will (irādah), and goal (qasd) are various terms that all mean the same thing, and it is a description of the state of the heart when it is a source for two things: knowledge and action.
Knowledge comes first – as it is the foundation and condition – and action follows it, since it is the fruit that branches from knowledge. This is because every action – that is, every intentional movement and motion – does not occur without three things: knowledge, will, and ability. Nobody does something without knowing of it. So, he must have knowledge. Likewise, nobody does something without having the will to do it. So, one must have the will to do something, and the meaning of will (irādah) is that the heart reaches out to what it sees as being in accordance with what it seeks.
The human was created such that he sometimes does that which is in accordance with what his heart seeks, and sometimes does that which conflicts with what his heart seeks. In such a case, he needs to draw near to that which is good for him, and to drive away what will harm him. This requires that he know and understand what will benefit and harm him, such that he can bring this close and avoid that, since whoever does not see or know what food is cannot reach over and pull it towards him, and whoever does not see fire cannot escape from it. So, Allāh has Created guidance and knowledge, and has provided certain means of attaining them, and these are the external and internal senses.
So, intention is essentially the will and the act of reaching out to and leaning towards what one seeks, whether this occurs retrospectively or at the time of seeing what is sought after. Therefore, the first step in one being pushed to do something is that he has a goal which motivates him to act, and goal is the target of one’s intention. One is pushed to go out and do something when he has a goal and intention, and directs his power and ability towards his goal by way of physical movement, and this is known as action…”
[Excerpts taken from book ‘The Manners of the Knowledge Seeker’]