Umar ibn Al Khattab (ra) reported that Allah’s Messenger (saws) said: “For everything there is a polish, and the polish for the hearts is the dhikr of Allah. There is nothing more potent in saving a person from the punishment of Allah than the dhikr of Allah”
The idea of polishing the heart can seem alien at first. “Polishing” evokes images of scrubbing hard at rusty trophies. But this metaphor has been used because the reality of the heart is actually quite similar.
This is illustrated in another hadith of Muhammad (saws) said: “There is one muscle in the body and if it is a pure the whole body is pure, if it is rotten the whole body is rotten. Verily it is the heart.”
As Muslims, we all go through dips in our iman, but the beauty of the Deen is that every minute is a chance to improve ourselves and change our character. It is for this reason that we are warned against developing diseases of the heart.
All diseases of the heart originate from two things: neglecting the remembrance of Allah and engaging in sinful actions
As someone distances themselves from actions that are beloved to Allah, the heart attracts rust. Its good qualities are eroded and it becomes so concerned with the superficial delights of this world that it leaves behind the moral compass Islam gives us. Eventually, the heart becomes so rusty that one will no longer be able to differentiate the truth from the falsehood and their perception will become corrupted. But the greatest calamity is that they will no longer find acts of submission towards Allah (swt) desirable. It becomes blinded, following only its whims and desires.
This can then manifest in a variety of characteristics including jealousy, envy, harshness, backbiting, slander, pride, hypocrisy; all traits we are advised against developing in the Deen. Not only are these qualities harmful to others, but also they are primarily detrimental to our own selves. These qualities are self-destructive, that make us constantly unhappy with our lives, which turn our friends away from us and make us unable to forgive others and move on.
So how can we cure ourselves from diseases of the heart?
As with anything in life, Islam does not leave us wanting for answers. And in the very hadith that Muhammad (saws) talks about polishing the heart, he gives us the solution of how to go about it: Dhikr (remembrance) of Allah (swt).
Muadh ibn Jabal relates that Muhammad (saws) was asked: What action is the most beloved to Allah? He replied: “That you continue to keep your tongue moist with the dhikr of Allah until you die”
Dhikr is one of the most beautiful and easy acts to do in Islam. By glorifying Allah (swt) with the words Allahu Akbar, Alhamdulilah, SubhanAllah, we are reminded of some of Allah’s greatest qualities, his majesty, the fact that He deserves all our gratitude and praise. Repeating astaghfirullah reminds us that Allah (swt) is our only source of redemption, and aside from forgiving us, He rewards us for even seeking forgiveness from him! How merciful is our Lord.
Calling upon Allah with His 99 names are other adhkaar that are easy to engage in, and remind us that Allah is Al Wadud, the Most Loving, Ar Raheem, the most merciful and Al Salam, the source of peace. Whether you have a tasbeeh or doing it on your fingers, it’s the easiest form of ibadah to do. Wherever you are, whatever you’re doing, you need only repeat a few phrases to keep your heart pure and attain masses of reward.
Muhammad (saws) is reported to have said: “Whoever says “SubhanAllahi wa bihamdihi” a hundred times during the day, his sins are wiped away, even if they are like the foam of the sea”. In another narration Abu Dharr reported that the Prophet (saws) said, “Shall I tell you the words that Allah loves the most?” I said: “Yes, tell me, O Messenger of Allah.” He said: “The words dearest to Allah are: subhanAllahi wa bihamdihi”. Muhammad (saws) also noted that a palm tree is planted for the reciter every time he says these words. All of these rewards for such an easy act subhanAllah!
Reciting the Quran is also a dhikr and reading Allah’s words is a reminder of His majesty and the miracle that He revealed to guide us in our lives. Even if its just three verses a day, that connection with the book of Allah is unique because this is how Allah (swt) communicates with us.
But engaging in remembrance of Allah (swt) does not only extend to specific actions of worship. Every action we do can be a source of reward for us if we perform it with the correct intention. This can be something as small as starting our meal with Bismillah, or something bigger, like attending a halaqah (circle on Islam), advising a friend, helping your neighbour. There are avenues for reward and opportunities for purification everywhere if we care to look.
 Saheeh: Related by Ahmad (4/352), from Mu’aadh ibn Jabal radiallaahu ‘anhu. It was authenticated by al-Albaanee in Saheehul-Jaami’ (no.5644).
 Sahih Bukhari 11:208, Muslim 1:539
 Sahih Bukhari #7:168, Sahih Muslim #4: 2071
 At Tirmidhi 5:511, Al Hakim