An example by Imaam Al-Ghazzali

An example of the inner reality of the heart that Imaam Al-Ghazzali gives:

The Body is like a city and the perceptive power - the Mind (Akl) is a King that rules over the city. The perceptive power of the senses (sight, smell, touch, hearing) both external and internal are its armies and helpers.  The members (limbs) are like the people of the city, the soul which commands to evil – appetence and anger (nafs) is like the enemy who opposes the Kingdom and strives to destroy his people. His body thus becomes a frontier outpost, and his soul, is a place in which guards are placed. So if he strives against the enemy (nafs) and conquours him, then his deeds will be praised on the day that he returns to the presence of Allah (swt). But if he loses the control of the frontier and neglects his people, then his deeds will be blamed and vengeance will be taken against him when he meets Allah.

And so on the outside of the city, we have the evil notions (shaytaan) that try to penetrate the heart – the Castle, to take over the city, through different doors/gates. And it is the enemy within (your nafs) which tells the shaytan which doors are open, because your nafs knows you from the inside, it knows your weaknesses. And thus, we need the Akl – the intellect to understand and to keep closing the doors, to try to win the war.

Your Heart is where the battle takes place within the city. There are lesser battles and there are greater battles, the greater battle being that of the nafs – the battle against yourself.

Allow your Intellect (the King) to close the gate to the Heart (the Castle) in order to win the Battle of the Self (the Nafs)