Tafsir of Ash-Shu`ara' 26:192

{And indeed, it is a revelation of the Lord of the worlds.}

{And indeed, it is}: Meaning this revelation, that is, what has been sent down of these stories and verses.

The meaning of "revelation" (at-tanzīl): It means the "revealed" (al-munazzal). The bā’ in {The Trustworthy Spirit has brought it down} (193) and {has brought it down} (in the two variant readings) is for the purpose of transitivity.

The meaning of {The Trustworthy Spirit has brought it down}: God made the Spirit descend with it.

{Upon your heart}: That is, He preserved it for you and made you understand it, establishing it in your heart with an establishment that is never forgotten, as in His saying: {We will make you recite, and you will not forget} (Al-A‘lā: 6).

{In a clear Arabic language}:

1. It may relate to {the warners} (194). The meaning would be: "So that you may be among those who warned in this language," and they are five: Hūd, Ṣāliḥ, Shu‘ayb, Ismā‘īl, and Muḥammad (peace be upon them all).
2. It may relate to {brought it down}. The meaning would be: "He brought it down in the Arabic language so that you may warn with it." For if He had brought it down in a non-Arabic language, they would have shunned it entirely, saying: "What are we to do with what we do not understand?" and warning through it would have been impossible.

In this second interpretation, its revelation in Arabic—which is your language and the language of your people—is a revelation "upon your heart," because you understand it and your people understand it. If it were non-Arabic, it would have descended upon your hearing rather than your heart, for you would hear the ringing of letters whose meanings you do not grasp or retain.

A man may be proficient in several languages, but when he is spoken to in the language he was first taught, raised upon, and naturally inclined toward, his heart is directed solely toward the meanings of the speech, receiving them directly. He hardly notices how the words are structured. But if he is spoken to in another language, even if he is skilled in it, his focus is first on the words, then on the meanings. This confirms that it descended upon his heart because it descended in a clear Arabic language.

{And indeed, it is}: Meaning the Qur’an, its mention is established in all the heavenly scriptures. It is said: its meanings are contained within them. This is used as an argument for Abū Ḥanīfah regarding the permissibility of reciting in Persian during prayer—on the basis that the Qur’an remains the Qur’an even if translated into a language other than Arabic—since it is said: {And indeed, it is in the scriptures of the former peoples} (196), due to its meanings being present therein.

It is also said: The pronoun refers to the Messenger of God (peace be upon him), as is the case in {that the scholars of the Children of Israel know it} (197), but this is not clear.