"Say, 'The knowledge is only with Allah,'" meaning the knowledge of the Hour; none knows its coming except Him. "'And I am only a warner,'" I warn you of the punishment of Allah, "'clear,'" clarifying to you from Allah.
﴿قُلْ إِنَّمَا الْعِلْمُ عِنْدَ اللَّهِ﴾ يَعْنِي عِلْمُ السَّاعَةِ لَا يَعْلَمُ قِيَامَهَا إِلَّا هُوَ ﴿وَإِنَّمَا أَنَا نَذِير﴾ أنذركم عَذَاب الله ﴿مُبين﴾ أبين لكم عَن الله