The first verse instructs that a person can only benefit from his own deeds. The second verse describes the condition of Ibrahim (sallallahu ‘alayhi wa sallam) with his Lord.

First, we will explain what is meant by the ‘sound heart’ then we will clarify the meaning of this Quranic expression and what is really intended by it. Linguistically speaking, ‘Saleem’ (sound) is derived from the root verb ‘Salima’. ‘Qalbun Saleem’ (a sound heart) is the heart free from diseases and abnormal conditions. As for the specific legal meaning, a sound heart knows nothing but Islam. This term ‘Saleem’ shares its linguistic root with the word ‘Islam’, and the significance of this is not hidden.

Several sayings were reported from the Righteous Predecessors regarding the meaning of the sound heart, among which are the following:

Ibn ‘Abbas (may Allah be pleased with them both) said: “The sound heart is the living heart, bearing witness that there is no deity worthy of worship except Allah.”

Mujahid said: “The sound heart harbors no doubt.”

Qatadah said: “The sound heart is the one free from polytheism."

Ibn Zayd said: “The sound heart is the one free from polytheism; as for sins, no one is safe from them.”

Ad-Dahhak said: “The sound heart is the sincere one.”

Ibn Sireen said: “The sound heart is the one knowing that Allah is true, that the Hour is coming without doubt, and that Allah will resurrect those in the graves.”

Ibn Al-Musayyib said: “The sound heart is the healthy heart and it is the heart of the believer. The heart of the non-believer and the hypocrite is sick; Allah, the Almighty said, describing the hypocrites: “In their hearts is a disease” [Quran 2: 10]

Abu ‘Uthman Al-Naysaburi said: “The sound heart is the heart that is free from heresy and is reassured by the Sunnah.”

Considering the views of the Quran exegetes, we find their leading scholar At-Tabari views that the “sound heart” is the one safe from doubt in the Oneness of Allah and the resurrection after death. Ar-Razi believes the sound heart indicates the soul’s safety from ignorance and moral vices. Ibn ‘Ashour states that the sound heart is pure from the beliefs of polytheism, and that purity is attributed to the purity of the soul. Shaykh As-Sa’di mentions that the sound heart is free from polytheism, doubt, love of evil, insistence on religious innovation, and sins. All these views are close, mutually supportive, and explain each other.

The important thing here, as scholars stressed, is that a person would not have a sound heart unless he possesses the morals of the Noble Quran. Therefore, the Prophet’s morals (sallallahu ‘alayhi wa sallam) were derived from the Quranic percepts, as mentioned in a Hadith. One of the characteristics of a healthy heart is that it is full of Islam and is adorned with the manners inculcated in it by the Quran. If not, it cannot be described as a sound heart.

It is good to note that the sound heart is free from everything that harms people. In an authentic Hadith it was narrated that the Prophet (sallallahu ‘alayhi wa sallam) said: “A Muslim is the one from whose tongue and hands the Muslims are safe.” (Agreed upon by Al-Bukhari and Muslim)

Based on the above-mentioned statements, the believer’s heart must be free from unbelief, polytheism, doubt, hesitation, and emptiness. A heart that is filled with disbelief, no matter how humanely its owner acts, will not be sound. A heart devoid of faith does not know the path of good. If it happens to know it, it uses it for some pursued benefit, whether apparent or hidden.

Without faith, the images of goodness, beauty, and virtue are either a lie or something transient. Therefore, it (such a heart) is devoid of any real value.

We may hear some people say, “My heart is clean because I love people very much, and I strive to help them.” This, after contemplation and investigation, makes no sense; the heart that is inhabited and permeated by atheism and denial would not be clean nor sound.

Here are some tips about the sound heart that we mention to maximize the benefit:

The first tip: Allah’s saying “with a sound heart” brings together the collective aspects of the soul’s perfection. These collective aspects are the source of praiseworthy deeds. It is stated in a Hadith “Beware! There is a piece of flesh in the body which if sound the entire body is sound, and if corrupt the entire body is corrupt, and that is the heart.” (Agreed upon by Al-Bukhari and Muslim)

The second tip: The heart, to be safe from polytheism and doubt, “must be characterized by their opposites, including sincerity, knowledge, certainty, love of goodness, and endearing it in one’s heart. Will and love of the heart should be subservient to Allah’s love, and his desires should be according to what was revealed from Allah.” (Shaykh As-Sa’di)

The third tip: The Noble Quran sets the “good heart” against money and children. This link has significance; wealth and children are often a barrier between a person and the path of righteousness. In this sense, the Almighty said, warning and cautioning: "Wealth and children are [but] adornment of the worldly life. But the enduring good deeds are better to your Lord for reward and better for [one's] hope." [Quran 18: 46] "And know that your properties and your children are but a trial.” [Quran 8: 28]

In conclusion, caring for the heart is a very important matter, especially since many people have neglected it. It is no secret that dedication to reform, monitor, and correct this heart so that it becomes sound and healthy, is something that should not be overlooked.