Source: Al-Fawaaid – A COLLECTION OF WISE SAYINGS – Imam Ibn AI-Qayyim,
Rendered into English by: Bayan Translation Services
In order for a place to contain something, it must be free from whatever contradicts it. This principle appljes to mankind and all creation as well as to belief and desires.
So, if the heart is obsessed by belief in falsehood, there will be no place for truth. Accordingly, if the tongue is involved in trivial discourse, one shall be incapable of useful speech, unless falsehood is abandoned.Hence, if the body is busy doing wrong actions, then acts of worship will be inapplicable unless these contradictory actions are abandoned.
This is how this principle is applied to concrete objects, and it is also applied to belief and religion. If the heart deviates from loving Allah, lacks yearning for Him and longing for His closeness, then the removal of contradictory feelings, like being related to other than Allah, is the only way for this heart to be overwhelmed by love for Allah.
For the tongue to remember Allah, and the body to serve Him, one should be free of the impact of others like being busy remembering and serving them. Thus, if the heart is overwhelmed by the servants rather than the master, and is preoccupied with futile knowledge, surely there will be no place for being closer to Allah, or being acquainted with His Names, Attributes and judgments.
If the heart listens to trivial discourse, there will be no place for listening or understanding the words of Allah. Besides, if the heart is inclined to love others, there will be no room to love Allah, and if the heart remembers others rather than Allah, no place will be found to remember Him, and the same applies to the tongue.
Al-Bukhary recorded that the Prophet (peace be upon him) said, “It is better for any of you that the inside of his body be filled with pus which may consume his body, than it be filled with poetry”‘ 
This Prophetic tradition explained that it is possible that the inside of one’s body may be filled with poetry, which means that it might be exposed to suspicion, doubts, illusions, uncertainties, futile knowledge, and trivial discourse. So, if the heart is filled with such things, the facts of the Quran and precious knowledge, which cause happiness and perfection in mankind, will find no room in that heart.If a heart receives advice but it is filled with what contradicts it, there will be no place in that heart to accept this advice. The advice will simply pass over this heart and not be able to settle in it.
 Recorded by AI-Bukhary, in His Sahib, Book of AI-Adab (Good Manners and Form), Chapter on not recommending poetry, no. (6154), and recorded by Muslim in His Sahib no. (2258)