Tafsir of At-Taghabun 64:11

{Except by the permission of Allah} Except by His decree and His will; it is as if He gave permission for the calamity to strike him.

{He guides his heart} He treats him with kindness and expands his heart to increase in obedience and goodness. It is also said: It is the act of saying Istirja‘ (Inna lillahi wa inna ilayhi raji‘un) when a calamity strikes.

Al-Dahhak said: He guides his heart until he knows that what struck him could not have missed him, and what missed him could not have struck him.

Mujahid said: If he is tested, he is patient; if he is given, he is grateful; and if he is wronged, he forgives.

It is also recited as yuhdā qalbuhu (passive voice), with al-qalb being in the nominative or accusative case. The accusative case is interpreted like the phrase safaha nafsahu (he made his soul foolish), meaning: he is guided in his heart.

It is also possible that the meaning is: The disbeliever is astray from his heart, distant from it, while the believer finds it and is guided to it, as in His saying: {For whoever has a heart} (Qaf: 37).

It is also recited as nahdī qalbahu (with a nun). And yahiddu qalbuhu in the sense of yahtadī (he is guided). And yahda’u qalbuhu (with a hamza) means: his heart finds tranquility. And yahiddu and yahda’u are also recited with lightened vowels.

{And Allah is Knowing of all things} He knows which hearts are affected by His kindness and which are not, so He grants it to whom He wills and withholds it from whom He wills.

{And obey Allah and obey the Messenger; but if you turn away - then upon Our Messenger is only the clear notification. Allah - there is no deity except Him. And upon Allah let the believers rely.}