This is the truthful and sound (salim) heart. It is the only type of heart that person can bring to Allah on the Day of Judgement which will rescue him. Allah, Exalted is He says, “…the Day when neither wealth nor sons will be of any use – except for he who comes to Allah with a sound and flawless heart.” (Surah al-Shuara 26:88-89)
The meaning of salim (secure) is saalim (the one who is secure), it has come in this form because it depicts an innate attribute or description of the described. As such it is grammatically like the words tall (tawil), short (qasir), or graceful and charming (zarif).
Therefore the one whose heart is described as salim is characterised so because this attribute of truthfulness and soundness has become its constant and established quality. In this respect it is like the terms, ‘the one who knows’ (alim) and the ‘one who has power’ (qadir).
It is also the opposite of diseased (marid), sick (saqim), and ailing (alil).
People have described the sound and truthful heart in different ways. However they all revolve around the following basic concept,
The truthful and sound heart is that which is secure from every carnal desire that opposes the order and prohibition of Allah. It is secure from every doubt and uncertainty that would obscure or go against His narrative. It is secure from displaying servitude from seeking ruling from any other than His Messenger, peace and blessings of Allah be upon him. Therefore it becomes sound through loving Allah and seeking the ruling of the Messenger. It becomes sound through showing Him fear, hope, trust and reliance, pentinence, and humility; it prefers what pleases Him in every circumstance and distances itself from everything that would displease Him in every possible way. This is the reality of servitude (ubudiyyah) which can only be directed to Allah Alone.
Therefore the truthful and sound heart is that heart which is secure from committing any form of shirk whatsoever and instead its servitude is directed only to, and purely for, Allah, Exalted is He. Its desire, love, trust and reliance, penitence, humility, fear and hope is only for Allah and its actions are purely for His sake. Hence if it loves, it loves for the sake of Allah; if it hates, it hates for the sake of Allah; it if gives, it gives for the sake of Allah; and if it withholds, it withholds for the sake of Allah.
But this alone does not suffice until the heart becomes secure from submitting to, and going to, anybody else but the Messenger of Allah, peace and blessings of Allah be upon him, for judgement. Therefore the heart ties a firm bond with him, resolving to follow him and obey him alone in sayings and actions. These sayings compromise the saying of the heart: the matters of belief; and the sayings of the tongue: this conveys what the heart contains. These actions comprise the actions of the heart: its desire, love, dislike and other connected matters; and the actions of the limbs.
Therefore the judge for all these maters – the major and minor of them – is that which the Messenger, peace and blessings of Allah be upon him, came with. Hence the heart does not put itself before him in any manner related to belief, saying, or action. Allah, Exalted is He, says, “O you who believe! Do not put yourself forward in front of Allah and His Messenger…” (Surah al-Hujurat 49:1) Meaning: do not speak of a matter until he has spoken of it and do not act until he has commanded it.
Some of the Salaf said, “There is no action, even if it be small, except that two records will be unfurled for it: why? how?”Meaning: Why did you do it? How did you do it?
The first question enquires about the cause, onset and motive of the action. Was it done for some temporary and worldly gain such as attaining the praise of people? Was it done for fear of people’s censure? Or was the motivation of this action establishing the rights of servitude, seeking the increase of ones love of, and closeness, to Allah, Glorious and Exalted is He, and seeking the means of drawing close (wasilah) to Him?
The essence of the question is: Was it upon you to perform this action for the sake of your Master or for the sake of personal gain and base desires?
The second question enquires about the following of the Messenger, peace and blessings of Allah be upon him, in that action of worship: Was the action you did from those actions which have been legislated upon the tongue of My Messenger? Or was it an action that I did not legislate and was not pleased with?
Therefore the first question concerns sincerity (ikhlas) and the second concerns following (mutabah). Allah does not accept any action until both pre-requisites are met.
The method of absolution from the first question is to purify ones sincerity such that it is for Allah Alone.
The method of absolution from the second question is to actualise the following of the Messenger, peace and blessings of Allah be upon him, and by securing the heart from any intent that would impair its sincerity and any base desire that would impair its following.
This is the reality of the sound and truthful heart from which ensues victory and bliss.
Taken from Ighathatu’l l-Lahfan fi Masayid al-Shaytan, Vol 1, pp11-19 by Imam ibn al-Qayyim