Allah, the Exalted, says,

﴿أَفَلَمْ يَهْدِ﴾

(Is it not a guidance for them...) This is addressed to those who reject what the Prophet came to them with: `We destroyed those who denied the Messengers from the previous nations before them. They showed open hostility, so now there is not trace of them and none of them are left. This is witnessed by the empty homes that these people left behind, and which others have now inherited, moving about in the dwellings of those of the past.'

﴿إِنَّ فِى ذلِكَ لأيَـتٍ لاٌّوْلِى النُّهَى﴾

(Verily, in this are signs indeed for men of understanding.) This means those who have sound intellect and correct understanding. This is as Allah says,

﴿أَفَلَمْ يَسِيرُواْ فِى الاٌّرْضِ فَتَكُونَ لَهُمْ قُلُوبٌ يَعْقِلُونَ بِهَآ أَوْ ءَاذَانٌ يَسْمَعُونَ بِهَا فَإِنَّهَا لاَ تَعْمَى الاٌّبْصَـرُ وَلَـكِن تَعْمَى الْقُلُوبُ الَّتِى فِى الصُّدُورِ ﴾

(Have they not traveled through the land, and have they hearts wherewith to understand and ears wherewith to hear Verily, it is not the eyes that grow blind, but it is the hearts which are in the breasts that grow blind.) ﴿22:46﴾ Allah also said in Surah Alif Lam Mim As-Sajdah,

﴿أَوَلَمْ يَهْدِ لَهُمْ كَمْ أَهْلَكْنَا مِن قَبْلِهِمْ مِّنَ الْقُرُونِ يَمْشُونَ فِى مَسَاكِنِهِمْ﴾

(Is it not a guidance for them: how many generations We have destroyed before them in whose dwellings they walk about) ﴿32:26﴾ Then, Allah, the Exalted, says,

﴿وَلَوْلاَ كَلِمَةٌ سَبَقَتْ مِن رَّبِّكَ لَكَانَ لِزَاماً وَأَجَلٌ مُّسَمًّى ﴾

(And had it not been for a Word that went forth before from your Lord, and a term determined (their punishment), must necessarily have come (in this world).) ﴿20:129﴾ This means that if it were not for the Word that had already preceded from Allah -- that He would not punish anyone until the proof had been established against him and the punishment would take place at an appointed time that He has already determined for these rejecters -- then the punishment would certainly seize them immediately.