Itikaf is the epitome of fasting. While fasting in Ramadan, from dawn till dusk, one abstains from food, drink and marital relations. But in itikaf, one goes a step further and imposes even more restrictions on oneself. This is when a person abandons his home, family, business and all worldly interests and settles in a mosque. Earlier he had to avoid relations with wife only during the day, but now even during the night he has to forgo this strongest of human desires. Earlier, one could meet other people, but now, avoiding everyone, one devotes oneself only to God. In this way, a believer leaves the whole world and worldly affairs except for one sign of life, i.e. eating and drinking at night, settles in the house of Allah, and spends his morning and evening in His remembrance and His devotion.
The restrictions of itikaf make a person realize that the blessings of Allah are so great, that the rightful thing to do is to live the entire life like this. But it is the mercy of God that He did not make this worship mandatory, and neither did He force man to please Him by forgoing food, drink, family, marital relationship, business, social relations and worldly affairs at all times. All He asks of us is not to forget Him while indulging in all these.
You may marry, build a house, run a business, do a job, share joys of family, enjoy the world and its interests within reason, but remember Me. Do not disobey Me. Because life in this world is not eternal. As the days of Ramadan and itikaf pass by, so will this worldly life. You will then return to Me. Lest you have nothing but regrets that day. This is the real teaching of itikaf.
Translated by Ali Zafar