Imam explains the matter through his theological works as following:
If someone is able to do this, he has reached a great felicity. However, with the least attention to this world it is impossible to be cut off from all else but Allah.
Someone who wants to perform the fast of the blessed month of Ramadan with such manners as he has been asked to, must cut himself off completely from all else so that he can observe the manners for the celebration and feast [of Allah], coming to know of the station of the Host, insofar as this is possible.
In this noble month, in which you have been invited to the divine banquet, if you do not gain insight [ma‘rifat] about God the Almighty nor insight into yourself, it means that you have not properly participated in the feast of Allah.
You must not forget that in this blessed month, which is the ‘month of Allah’, in which the way of divine mercy is opened to the servants of God and the satans and devils, according to some reports, are locked in chains.
If you are not able to reform and refine yourselves, and to manage and control your nafs al-ammarah [the commanding soul], to subdue your selfish lusts and to cut off your relations and interests with this world and material things, then after the end of the month of fasting it will be difficult for you to be able to accomplish this, Imam further explained.
Therefore, take advantage of this opportunity before the magnificent grace of it vanishes, and purify and reform yourselves.
Imam Khomeini further advises faithful people to get ready and prepare to perform the duties of the month of fasting. Let it not be that prior to the arrival of the month of Ramadan you are like one who is wound up by the hand of Satan so that in this single month when the satans are enchained you automatically busy yourselves with sin and deeds opposed to the orders of Islam!
Sometimes due to his distance from God and the great number of his sins, the rebellious and sinful man sinks so low into darkness and ignorance that he does not need Satan to tempt him, but he himself takes on the color of Satan. “Sibghatullah” is the opposite of the color of Satan.
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Imam Khomeini warned against pursuing selfish desires