Tafsir Ibn Kathir -> Surah Ibrahim -> Disbelievers reject Prophethood because the Messengers were Humans!

Their nations said,

﴿إِنْ أَنتُمْ إِلاَّ بَشَرٌ مِّثْلُنَا﴾

(You are no more than human beings like us!) so why should we follow you just because you say so, even though we did not witness a miracle by your hands,

﴿فَأْتُونَا بِسُلْطَـنٍ مُّبِينٍ﴾

(Then bring us a clear authority.), a miracle of our choice.

﴿قَالَتْ لَهُمْ رُسُلُهُمْ إِن نَّحْنُ إِلاَّ بَشَرٌ مِّثْلُكُمْ﴾

(Their Messengers said to them: "We are no more than human beings like you...'') affirming that truly, they were only human being like their nations,

﴿وَلَـكِنَّ اللَّهَ يَمُنُّ عَلَى مَن يَشَآءُ مِنْ عِبَادِهِ﴾

(but Allah bestows His grace to whom He wills of His servants.), with prophethood and messengership which is His choice,

﴿وَمَا كَانَ لَنَآ أَن نَّأْتِيَكُمْ بِسُلْطَـنٍ﴾

(It is not ours to bring you an authority) according to your choice,

﴿إِلاَّ بِإِذْنِ اللَّهِ﴾

((except by the permission of Allah. ), after we beg Him and He provides us with a miracle,

﴿وَعَلَى اللَّهِ فَلْيَتَوَكَّلِ الْمُؤْمِنُونَ﴾

(And in Allah (alone) let the believers put their trust.) in all their affairs. Their Messengers said to them next,

﴿وَمَا لَنَآ أَلاَّ نَتَوَكَّلَ عَلَى اللَّهِ﴾

(And why should we not put our trust in Allah), after He had guided us to the best, most clear and plain way,

﴿وَلَنَصْبِرَنَّ عَلَى مَآ آذَيْتُمُونَا﴾

(And we shall certainly bear with patience all the hurt you may cause us), such as foolish actions and abusive statements,

﴿وَعَلَى اللَّهِ فَلْيَتَوَكَّلِ الْمُتَوَكِّلُونَ﴾

(and in Allah (alone) let those who trust, put their trust.)

﴿وَقَالَ الَّذِينَ كَفَرُواْ لِرُسُلِهِمْ لَنُخْرِجَنَّـكُمْ مِّنْ أَرْضِنَآ أَوْ لَتَعُودُنَّ فِى مِلَّتِنَا فَأَوْحَى إِلَيْهِمْ رَبُّهُمْ لَنُهْلِكَنَّ الظَّـلِمِينَ - وَلَنُسْكِنَنَّـكُمُ الاٌّرْضَ مِن بَعْدِهِمْ ذَلِكَ لِمَنْ خَافَ مَقَامِى وَخَافَ وَعِيدِ - وَاسْتَفْتَحُواْ وَخَابَ كُلُّ جَبَّارٍ عَنِيدٍ - مِّن وَرَآئِهِ جَهَنَّمُ وَيُسْقَى مِن مَّآءٍ صَدِيدٍ - يَتَجَرَّعُهُ وَلاَ يَكَادُ يُسِيغُهُ وَيَأْتِيهِ الْمَوْتُ مِن كُلِّ مَكَانٍ وَمَا هُوَ بِمَيِّتٍ وَمِن وَرَآئِهِ عَذَابٌ غَلِيظٌ ﴾

(13. And those who disbelieved, said to their Messengers: "Surely, we shall drive you out of our land, or you shall return to our religion.'' So their Lord revealed to them: "Truly, We shall destroy the wrongdoers.'') (14. "And indeed, We shall make you dwell in the land after them. This is for him who fears standing before Me and also fears My threat.'') (15. And they sought victory and help; and every obstinate, arrogant dictator (who refuses to believe in the Oneness of Allah) was brought to a complete loss and destruction.) (16. In front of him is Hell, and he will be made to drink boiling, festering water.) (17. He will sip it unwillingly, and he will find great difficulty in swallowing it down his throat, and death will come to him from every side, yet he will not die, and in front of him, will be a great torment.)