Fatir 35:45

Walaw yu-akhithu Allahuannasa bima kasaboo ma taraka AAalathahriha min dabbatin walakinyu-akhkhiruhum ila ajalin musamman fa-itha jaaajaluhum fa-inna Allaha kana biAAibadihi baseera

And if Allāh were to impose blame on the people for what they have earned, He would not leave upon it [i.e., the earth] any creature. But He defers them for a specified term. And when their time comes, then indeed Allāh has ever been, of His servants, Seeing.

If Allah were to take mankind to task for what they did, He would have not left a living creature on its back, but He delays them upto an appointed time. So when their time will come, then Allah is the One who will see His slaves.