Concerning Allah's statement,

﴿وَلَئِن قُلْتَ إِنَّكُمْ مَّبْعُوثُونَ مِن بَعْدِ الْمَوْتِ﴾

(But if you were to say to them: "You shall indeed be raised up after death.'') Allah, the Exalted, is saying, "O Muhammad, if you were to inform these polytheists that Allah is going to resurrect them after their death, just as He created them originally (they would still reject).'' Even though they know that Allah, the Exalted, is the One Who created the heavens and the earth, just as He said,

﴿وَلَئِن سَأَلْتَهُم مَّنْ خَلَقَهُمْ لَيَقُولُنَّ اللَّهُ﴾

(And if you ask them who created them, they will surely say: "Allah.'')﴿43:87﴾ Allah says,

﴿وَلَئِن سَأَلْتَهُمْ مَّنْ خَلَقَ السَّمَـوَتِ وَالاٌّرْضَ وَسَخَّرَ الشَّمْسَ وَالْقَمَرَ لَيَقُولُنَّ اللَّهُ﴾

(And if you were to ask them: "Who has created the heavens and the earth and subjected the sun and the moon'' They will surely reply: "Allah.'') ﴿29:61﴾ Even after their awareness of this (Allah's creating), they still reject the resurrection and the promised return on the Day of Judgement. Yet, in reference to ability, the resurrection is easier (for Allah to perform) than the original creation. As Allah said,

﴿وَهُوَ الَّذِى يَبْدَأُ الْخَلْقَ ثُمَّ يُعِيدُهُ وَهُوَ أَهْوَنُ عَلَيْهِ﴾

(And He it is Who originates the creation, then He will repeat it (after it has perished); and this is easier for Him.) ﴿30:27﴾ Allah also said,

﴿مَّا خَلْقُكُمْ وَلاَ بَعْثُكُمْ إِلاَّ كَنَفْسٍ وَحِدَةٍ﴾

(The creation of you all and the resurrection of you all are only as (the creation and resurrection of) a single person.) ﴿31:28﴾ Concerning the statement,

﴿إِنْ هَـذَا إِلاَّ سِحْرٌ مُّبِينٌ﴾

(This is nothing but obvious magic.) The polytheists say this due to their disbelief and obstinacy. They say, "We do not believe your claim that resurrection will occur.'' They also say, "He (Muhammad) only says this (resurrection of the dead) because he is bewitched, and he wants you to follow him in what his bewitchment tells him. Concerning Allah's statement,

﴿وَلَئِنْ أَخَّرْنَا عَنْهُمُ الْعَذَابَ إِلَى أُمَّةٍ مَّعْدُودَةٍ﴾

(And if We delay the torment for them till a determined term,) Allah, the Exalted, is saying "If We delay the torment and the destruction of these polytheists until an appointed time and a period determined, and We promise them a specific time period (of life), they would still say, in rejection and haste;

﴿مَا يَحْبِسُهُ﴾

(What keeps it back) They mean by this, "What delays this torment from overtaking us'' Both rejection and doubt are their very nature. Therefore, they have no escape or refuge from the torment.