Tafsir of Qaf 50:2

"Nay, they wondered that there came to them a warner from among themselves."

What was mentioned first is the relied-upon meaning. "Nay" (bal) is for idrab (turning away) from what the implicit answer to the oath signifies. It is as if it were said: "We have revealed it so that you may warn people through it, yet they did not believe in it; rather, they made both the warner and that which he warns about an object of arrogance and wonder, despite them being most consistent with the dictates of reason and most susceptible to acceptance."

It has been said: The underlying structure is "You have come to them as a warner of the Resurrection, yet they did not accept it, but rather wondered—or they doubted it, but then wondered." The meaning is that they did not suffice with doubt and rejection, but were certain of the contrary, to the point that they treated this as one of the strange affairs.

It has also been said: It is an idrab from what is understood from describing the Quran as "Majid" (Glorious). It is as if it were said: "The cause of their refusal to believe in the Quran is not that it lacks glory, but rather their ignorance." Through the Almighty’s words, "Nay, they wondered," He draws attention to this, for wondering at a thing necessitates ignorance of its cause. It is stated in al-Kashf: "This is an excellent interpretation."

"That there came to them" (an ja’ahum) implies li-an ja’ahum (because there came to them). The meaning of "from among themselves" (minhum) is from their own species; that is, from the human species or from the Arabs. The plural pronoun in the verse returns to the disbelievers. It is also said it returns to "people," though that is not as strong.

"And the disbelievers said, 'This is a strange thing.'"

This is an explanation of their wonder, as it is accompanied by the height of denial, with added detail regarding the object of their wonder. This is a reference to the fact that he—upon him be peace—is a warner by means of the Quran. The pronoun was hidden [in the verb "wondered"] first to signify that they are specifically meant by what is attributed to them, and the noun was made explicit second to record against them the disbelief that resulted from it.

Alternatively, it is a conjunction of their wonder at the Resurrection to their wonder at the Prophetic mission. It is conjoined with the particle fa because it follows it and branches out from it; for if the one sent is denied, then that which he was sent with is also denied. Furthermore, "this" refers to something implicit, which is the Resurrection, explained by the subsequent denial-based sentence. The context also indicates it, as it indicates there is something being warned about, and it is known that the warning of the Prophets—upon them be peace—is first and foremost about the Resurrection and what follows it.

The use of the noun in place of the pronoun is either because they have previously been described with that which necessitates their disbelief, or to signify that their wonder at the Resurrection—due to its indication of their underestimation of the power of Allah—is more heinous than the first, and more deeply rooted in being disbelief, given that they witness His power, Exalted is He, over that which is—by the measurement of reason—more difficult among His marvelous creations.