Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And those who have no knowledge) who do not know the Oneness of Allah, i.e. the Jews (say: Why doth not Allah speak unto us) directly, (or some sign come unto us) a sign confirming the prophethood of Muhammad (pbuh); for then, we would surely believe? (Even thus, as they now speak, spoke) similar words (those before them) their forefathers. (Their hearts are all alike) their words and hearts are the same. (We have made clear the revelations) the signs: the commands, prohibitions and your traits in the Torah (for people who are sure) who believe.
And they, that is the disbelievers of Mecca, who do not know, say, to the Prophet (s): ‘Why does God not speak to us?, [to say] that you are His Messenger; Why does a sign not come to us?’, of the sort we have requested in order to show your sincerity. So, in the same way that these [disbelievers] have spoken, spoke those before them, from among past communities, to their prophets, the like of what they say, in [their] obstinacy and demand for signs; their hearts are much alike, in terms of unbelief and stubbornness: this is meant as consolation for the Prophet (s). Yet We have made clear the signs to a people who are certain, [a people] who know that these are [God’s] signs and so they believe in them, for to request other signs would be obduracy.
And those, polytheists, without knowledge, of His Oneness, say, 'Why does God not speak to usḍ; Why does a sign not come to usḍ' So, spoke those before them, the like of what they say; their hearts are much alike, in terms of [their] ignorance of [His] Oneness and the words of God and His signs, since knowledge of these is a branch of the knowledge of [His] Oneness. Yet We have made clear [the signs], the proofs of Oneness and the modality of communion [with God], to a people who are certain.
Muhammad bin Ishaq reported that Ibn `Abbas said that Rafi` bin Huraymilah said to the Messenger of Allah, "O Muhammad! If you were truly a Messenger from Allah, as you claim, then ask Allah to speak to us directly, so that we hear His Speech.'' So Allah revealed,
(And when there comes to them a sign (from Allah) they say: "We shall not believe until we receive the like of that which the Messengers of Allah had received.'' Allah knows best with whom to place His Message. Humiliation and disgrace from Allah and a severe torment will overtake the criminals (polytheists and sinners) for that which they used to plot.) (6:124) and
(And those who expect not a meeting with Us (i. e. those who deny the Day of Resurrection and the life of the Hereafter) said: "Why are not the angels sent down to us, or why do we not see our Lord'') (25:21) and,
(Nay, everyone of them desires that he should be given pages spread out) (74:52).
There are many other Ayat that testify to the disbelief of the Arab idolators, their transgression, stubbornness, and that they asked unnecessary questions out of disbelief and arrogance. The statements of the Arab idolators followed the statements of the nations of the People of the Two Scriptures and other religions before them. Allah said,
(The People of the Scripture (Jews) ask you to cause a book to descend upon them from heaven. Indeed, they asked Musa (Moses) for even greater than that, when they said: "Show us Allah in public,'') (4:153) and,
(Likewise, no Messenger came to those before them but they said: "A sorcerer or a madman!'' Have they (the people of the past) transmitted this saying to these (Quraysh pagans)) (51:52-53).
Allah said next,
قَدْ بَيَّنَّا الآيَـتِ لِقَوْمٍ يُوقِنُونَ
(We have indeed made plain the signs for people who believe with certainty.) meaning, We made the arguments clear, prooving the truth of the Messengers, with no need of more questions or proofs for those who believe, follow the Messengers and comprehend what Allah sent them with. As for those whose hearts and hearing Allah has stamped and whose eyes have been sealed, Allah described them:
(Truly, those, against whom the Word (wrath) of your Lord has been justified, will not believe. Even if every sign should come to them, until they see the painful torment) (10:96-97).
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
They demanded hat either Allah Himself should come before them and say, "This is My Book and these are My Instructions for you to follow." Or, He should show such a Sign to them as would conclusively demonstrate that Muhammad (Allah's peace be upon him) was really a Messenger of Allah and that what he presented was revealed to him by Allah.
That is, "The objections and demands of those who are opposing the Truth today are not new. These are exactly the same as have always been put forward by those who go astray from the Right Way, as all the wicked people of all ages think alike and follow the same line of argument."
The demand that Allah Himself should speak to them was so absurd that it needed no reply. As to the other demand that Allah should show them a Sign, Allah answers that He has shown many clear Signs but those who are not inclined to believe cannot see them.
Not to speak of the other Signs, the most conspicuous Sign was the personality of Muhammad himself (Allah's peace be upon him). They knew everything about his life before Prophethood; the conditions of his country and nation and the circumstances and environment under which he was brought up and how he spent the first forty years of his life before his appointment as a Prophet;
And they who do not know say “Why does God not speak to usḍ; Why does a sign not come to usḍ” So spoke those before them the like of what they say; their hearts are much alike. Yet We have made clear the signs to a people who are certain. The speech kalām of God سبحانه is connected to all created things in their entities aʿyān and their traces āthār by the command to “Be!” amr al-takwīn [and it is also connected to] those who have been charged [with the law] by the prescriptive command amr al-taklīf. But whoever lacks the ear of comprehension is deaf to hearing the Real. He سبحانه addressed some among the people of the Book and they heard His address but they were not able to bear it and after they recognized the enormity of the signs they engaged in distortion and alteration. Included in the signs which He made manifest were that which removes the defect of anything other [than Him] al-ʿilla min al-aghyār and quenches the thirst from things that are better al-ghulla min al-akhyār. But what proofs even if they were plain and clear would suffice those whose due is wretchedness whose [wretchedness] has already comeḍ