سَيَذَّكَّرُ مَن يَخْشَىٰ
The command in the preceding verse was ذَكِّرْ: the tafʿīl form, transitive, a work done from outside. To remind.
The verb in this verse is يَذَّكَّرُ: its origin is yatadhakkaru, the tafaʿʿul form (V), with the assimilation of the tāʾ into the dhāl. Reflexive: he himself remembers, he tries to remember, he brings himself round.
The one who receives the command, that is, can perform tadhkīr — he can remind. But tadhakkur — the coming about of the remembering — is not in his hands. A door can be knocked on; its opening is the business of the one inside.
This is the counterpart at the level of grammar of the limit at al-Ghāshiya 88/21-22: "you are only one who reminds".
A note on the pattern. In Arabic the tafaʿʿul form most often states takalluf (taking a work upon oneself, doing it with effort). Tadhakkur, that is, is not a passive remembering that simply happens; it is a turning towards remembering. There is a will inside the word.
سَ (the sīn). The sīn at the head of the verb states the near future. At al-Ḍuḥā 93/5 the difference between sawfa and sīn was recorded: sawfa states a wider and more distant future. Here sīn has been chosen — that is, the remembering is not a distant possibility but a near result.
Root: خ-ش-ي. To fear. But in Arabic there are several words for fear, and the difference between them matters.
The distinction the lexicographers generally record is this: خَوْف (khawf) is fear in general — the unease felt at the possibility of harm; what is feared may not be known. خَشْيَة (khashya), by contrast, is the fear felt with knowledge of the greatness of what is feared; there is knowledge and reverence within it.
"Among His servants it is only those who know who feel khashya of God" (Fāṭir 35/28).
Khashya, then, is a result of knowledge. One who does not know may be afraid; but he cannot feel khashya, because khashya requires knowing what one stands before.
This distinction cannot be presented as a firm rule — there are places in the Qurʾān where the two words are used in place of one another. But the general tendency runs this way, and in this verse it is meaningful.
Khashya, that is, is not the result of remembering but its condition. The expected order would have been the reverse: the reminder is given, the person remembers, then he fears. The verse breaks this order.
It is worth dwelling on what this means. The verse does not say that the reminder creates something in a person; it says that it sets in motion something already there. The reminder is not water poured into an empty vessel; it is a spark touching something ready to catch.
This has the same structure as the second verse of Sūrat al-Baqara: "…a guidance for those who are mindful of God" (al-Baqara 2/2). The Book is guidance for those who carry the concern to guard themselves — that is, for the Book to work, a prior turning is needed. This circle was taken up in the section on al-Baqara; al-Aʿlā 10 gives the same principle in a single sentence.
And this has a practical consequence: the reminder does not work unless it finds something answering it in the one addressed. This is not the fault of the one who gives the reminder. The condition in the ninth verse may be recording exactly this fact.