And likewise, He saith: “And had We sent down unto Thee a Book written on parchment, and they had touched it with their hands, the infidels would surely have said ‘This is naught but palpable sorcery.’” Most of the verses of the Qur’án are indicative of this theme. We have, for the sake of brevity, mentioned only these verses. Consider, hath anything else besides the verses been established in the whole Book, as a standard for the recognition of the Manifestations of His Beauty, that the people might cling to, and reject the Manifestations of God? On the contrary, in every instance, He hath threatened with fire those that repudiate and scoff at the verses, as already shown.
This is the last of the quotes Baha'u'llah uses from the Qur'an in this part of His proofs of the Mission of the Bab.
And what a strange choice of quotes. Out of all the possible quotes He could have selected, why this one?
It touches on the question of what we would accept as proof. Many people, when asked what they would accept in such a circumstance, said the original teachings in the Prophet's own handwriting. But here, Baha'u'llah points out that even that won't satisfy many people, no matter what they say.
The standard offered by Muhammad in the Qur'an, and the primary one offered by Baha'u'llah here, is the words themselves, not the format.
When He says that the majority of the Qur'an is "indicative of this theme", He is not referring to the claim of sorcery. It is about the importance of the Word of God, whether oral or written. Over and over, throughout that Book, continual reference is made to the importance of these words. And this is the basis not only of Muhammad's claim, but the very same standard Baha'u'llah uses to encourage people to recognize the Bab.
He will talk about this more in the next paragraph, so we are not going to look at the implications here. Instead, we will focus on this paragraph alone.
Baha'u'llah seems to be reminding us that our response to the Word of God does not occur in a vacuum. We may be given the Word of God orally, as Muhammad and Jesus gave it, and we might deny it. Here He points out that we might be given it in a written form, but we can still deny it. There are countless reasons we may have for not believing, and every one of those barriers has to be overcome before we can accept it.
He has spent virtually this entire book identifying the veils that were preventing the uncle from recognizing his Nephew, and removing them one at a time, before even beginning to offer these proofs. Now it seems as if the uncle, and the reader, are prepared to approach the Writings of the Bab in such a way, and with such a spirit, that recognition is now possible.
But let's take a look at how we got here.
He began by quoting the Bible, and helping the uncle see how it firmly established both the criteria and the proof for Muhammad. Now He is doing the same thing with the Qur'an. With the previous example, the uncle already knew the answer towards which it was all leading. Here, it is a matter of following the same line of reasoning.
To be clear, though, this is not the self-referential reasoning that says "The Qur'an is true because it says it's true." It is a step by step approach to the words in such a way that we can see them without bias.
That is how we are to approach the Writings of the Bab. And it is exactly what was asked of us in the very opening line of this book. "No man shall attain the shores of the ocean of true understanding except he be detached from all that is in heaven and on earth." It is also a reminder of that qualifier from the second paragraph, that nobody can attain this unless we cease "to regard the words and deeds of mortal men as a standard for the true understanding and recognition of God and His Prophets."
In the end, the question we are forced to ask ourselves is not what format would we like our proof, but what would we accept as proof. In other words, what is it we are looking for when we ask for proof of the validity of the Cause?
But what about that last line? "...(H)e has threatened with fire those that repudiate and scoff at the verses..."
It is important to note that this threat does not refer those that do not believe. We are not being threatened for not recognizing. At no point do we feel that Baha'u'llah is condemning people for not believing. But this is very much directed at those who "repudiate and scoff at the verses". That is far more active than just denying. It is going a step further and condemning and making fun of.
It is also not directed at the Manifestation. It is directed toward the revealed Word of God, the very standard by which we can recognize that Revelation.
Baha'u'llah does not seem concerned if people make fun of Him, or even deny Him. But when they turn that scorn to the Word of God? That's a different matter altogether.