“…the heart is the machine that drives all acts of worship. It is what moves the entire body! As long as the heart is alive, then the limbs will be alive, and the soul will open itself up to worship. However, if the heart becomes diseased, then worship will become too heavy on the soul, leading to it eventually disliking and hating - and we seek refuge with Allah from this - worship. Because of this, Allah - the Glorified and Exalted - said, regarding the prayer:
وَإِنَّهَا لَكَبِيرَةٌ إِلاَّ عَلَى ٱلْخَاشِعِينَ
“…and truly, it is extremely heavy and hard except on those who are submissive…” [al-Baqarah; 45]
The prayer is heavy, because one’s legs and hands are not what get up for the prayer. What gets up for the prayer are the heart and the soul.
إِنَّ ٱلْمُنَافِقِينَ يُخَادِعُونَ ٱللَّهَ وَهُوَ خَادِعُهُمْ وَإِذَا قَامُوۤاْ إِلَى ٱلصَّلاَةِ قَامُواْ كُسَالَىٰ يُرَآءُونَ ٱلنَّاسَ وَلاَ يَذْكُرُونَ ٱللَّهَ إِلاَّ قَلِيلاً
“Verily, the hypocrites seek to deceive Allah, but it is He Who deceives them. And when they stand up for the prayer, they stand with laziness and to be seen of men, and they do not remember Allah but little.” [an-Nisa’; 142]
Because of this, it is the heart that stands up for worship. The limbs are simply slaves of this heart, carrying out what it commands them. If the heart is alive, then the soul will be alive, and worship will become beloved and sweetened to the hearts and the souls, and they will open up for it.
However, if the heart becomes diseased, then worship becomes too heavy on it. The heart is like the digestive system: right now, the most beloved thing to you is meat. However, if you develop an ulcer somewhere in your digestive system, then the meat - along with its fat and oil - becomes the most hated thing to it, since it is diseased. Sweets are also something that are beloved to the soul. For example, if you were fasting right now and were to break your fast on some desserts, then your soul would become satisfied with that, right? However, if one were to be stricken with diabetes, then he would not be able to handle these sugary foods, even if they were beloved to him.
The heart is like this: it must be strong so that it can handle worship that is strong. The stronger your heart becomes, then throw as much worship upon it as you wish. You would get up to pray at night, and you would cherish this prayer and consider sleep to be your enemy:
تَتَجَافَىٰ جُنُوبُهُمْ عَنِ ٱلْمَضَاجِعِ يَدْعُونَ رَبَّهُمْ خَوْفاً وَطَمَعاً
“Their sides forsake their beds, to invoke their Lord in fear and hope…” [as-Sajdah; 16]
He begins to forsake it because an enmity develops between him and his bed. He prays behind the imam, and he says to himself: “If only he would make the prayer longer,” so that he would increase in his opening up to this worship, and his tasting of its sweetness.
At times, I would pray a normal prayer with the people behind me, so I would elongate the prayer. The youth would then come to me and say (the hadith): “Whoever leads the people in prayer should go easy on them,” - the youth! And there was an old man behind me who was between 90 and 100 years of age - his face filled with light - and he would say to me: “Keep making the prayer long and do not answer them.” A man of 90 years getting pleasure out of a long prayer, and a youth of 20, who probably practices karate and judo, cannot handle the same prayer.
If he went to the soccer field and spent two hours playing there without becoming bored, then why would he become bored from hearing the Qur’an for five minutes? The difference between a short prayer and a long prayer is simply five minutes, so why does he become bored from these five minutes of Qur’an, yet he does not become bored from two hours of soccer? Why does he not get bored from standing for two hours staring at an inflated piece of leather, his heart attached to it?
Because, what stands up to pray is the heart, and what stands up for sports are simply the body and muscles.”
-by ‘Abdullah ‘Azzam (may Allah have Mercy upon him)