Tafsir Ibn Kathir -> Surah An-Nahl -> The Unseen belongs to Allah and only He has Knowledge of the Hour

Allah tells us of the perfection of His knowledge and ability to do all things, by telling us that He alone knows the Unseen of the heavens and the earth. No one knows anything about such things except for what Allah informs about as He wills. His complete power, which no one can oppose or resist, means that when He wants a thing, He only has to say to it "Be!'' and it is, as Allah says:

﴿وَمَآ أَمْرُنَآ إِلاَّ وَحِدَةٌ كَلَمْحٍ بِالْبَصَرِ ﴾

(And Our commandment is but one as the twinkling of an eye.) (54:50) meaning, whatever He wills happens in blinking. Thus Allah says here:

﴿وَمَآ أَمْرُ السَّاعَةِ إِلاَّ كَلَمْحِ الْبَصَرِ أَوْ هُوَ أَقْرَبُ إِنَّ اللَّهَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ﴾

(And the matter of the Hour is not but as a twinkling of the eye, or even nearer. Truly, Allah is Able to do all things.) iElsewhere, Allah says:

﴿مَّا خَلْقُكُمْ وَلاَ بَعْثُكُمْ إِلاَّ كَنَفْسٍ وَحِدَةٍ﴾

(The processes of creating you all and resurrecting you all are but like that of (the creation and resurrection of) a single person.) (31:28)