And (remember) when your Lord said to the angels: "Verily, I am going to place (mankind) generations after generations on earth." They said: "Will You place therein those who will make mischief therein and shed blood, - while we glorify You with praises and thanks (Exalted be You above all that they associate with You as partners) and sanctify You." He (Allah) said: "I know that which you do not know."