كَلّا ۖ بَل ۜ رانَ عَلىٰ قُلوبِهِم ما كانوا يَكسِبونَ

No indeed! Rather, their hearts have been sullied by what they have been earning.

EXEGESIS

Rāna is from rayn which means the rust that overcomes a valuable thing.^{‎[1]Raghib, p. 373.} In this context, the primary signification is overcoming and predominance.^{‎[2]Tabrisi, 10/687.}

EXPOSITION

This verse continues to build on the significance of the previous verses. It discusses the causal relationship between actions and the state of the heart. It indicates that committing sins creates rust on the hearts such that the rust veils the hearts from realising the truth.^{‎[3]Mizan, 20/234.} In this sense, rayn means the accumulation of sins on top of sins until they overcome the heart and veil it from seeing the truth.^{‎[4]Tabrisi, 10/689.} God commands the believers not to follow the steps of Satan and not to walk in the path of transgression (2:168, 2:208, 6:142, 24:21). This is because it slowly leads to drowning into sins which will consequently veil their hearts over time such that they cannot go back to repentance.^{‎[5]Tabrisi, 10/689.} The worst consequence of committing sins is its effect on the heart such that it will lead to being veiled from God.^{‎[6]Amthal, 20/30.} Many verses in the Quran describe the effects of sins on the heart: Those who dispute the signs of Allah without any authority that may have come to them – [that is] greatly outrageous to Allah and to those who have faith. That is how Allah seals the heart of every arrogant tyrant (40:35); Allah has set a seal on their hearts and their hearing, and there is a blindfold on their sight, and there is a great punishment for them (2:7).

Moreover, this verse indicates the causal relationship between actions and faith. Transgression affects the heart such that it denies the truth even if proofs are provided: Then after him We sent [other] apostles to their people. They brought them manifest proofs, but they would not believe something they had denied before. Thus do We seal the hearts of the transgressors (10:74).

INSIGHTS FROM HADITH

1. It is narrated that the Prophet said: ‘The multitude of sins corrupts the heart.’^{‎[7]Suyuti, 6/326.}
2. Zurārah has narrated that Imam al-Bāqir (a) said: ‘There is none from the servants except that there is a white spot in their heart. So when they commit a sin, a black stain appears in that white spot. Then, if they repent, the black stain goes away; and if, on the other hand, they continue sinning and become habitual in sins, the blackness increases until it overcomes the whiteness. If the whiteness is completely covered, its owner never returns to good and these are the words of God, the all-mighty: No indeed! Rather, their hearts have been sullied by what they have been earning [83:14].’^{‎[8]Kafi, 2/273, h. 20.}

Note: Many commentators report similar narrations from the Prophet.^{‎[9]Suyuti, 6/326.}

3. It is narrated that Imam al-Ṣādiq (a) said: ‘The heart rusts, so if you remind it with the graces of God the rust goes away from it.’^{‎[10]Tabrisi, 10/689.}
4. It is narrated that the Prophet said: ‘Truly, the hearts rust just as iron rusts.’ He was asked: ‘O Messenger of God, and what could polish it?’ He said: ‘Reading the Quran and remembering death.’^{‎[11]Mustadrak.W, 2/104, h. 1548.}
5. It is narrated that the Prophet said: ‘Study in groups, meet, and engage in discussions as it polishes the hearts. Verily, the hearts rust as the sword rusts, and its polish is hadith.’^{‎[12]Kafi, 1/141, h. 8.}

[1] Raghib, p. 373.
[2] Tabrisi, 10/687.
[3] Mizan, 20/234.
[4] Tabrisi, 10/689.
[5] Tabrisi, 10/689.
[6] Amthal, 20/30.
[7] Suyuti, 6/326.
[8] Kafi, 2/273, h. 20.
[9] Suyuti, 6/326.
[10] Tabrisi, 10/689.
[11] Mustadrak.W, 2/104, h. 1548.
[12] Kafi, 1/141, h. 8.