The Rocky Tract - 15:8 We do not send the angels except for a definite purpose, and then no one is given a deadline.
Why are angels sent to criminals?
The Cow/2:210 Are they waiting for Allah and the angels to come to them from the dense clouds? Then everything would be over and everything would be returned to Allah.

The Criterion/25:21 "Those who did not expect to meet Us said: "Either angels should descend on us or we should see our Lord". They were arrogant to themselves and had gone far in rebellion."
The Criterion/25:22 "The day when they see the angels will not be a pleasant day for the guilty. They will say: "We are completely surrounded"."

The Scatterers/51:31 "(Abraham said): "O messengers, what is your mission?"
The Scatterers/51:32 "They said, "We have been sent to a guilty people."
The Scatterers/51:33 To send upon them stones of clay...
The Scatterers/51:34 Marked by your Lord for the transgressors.

The Rocky Tract/15:57 "He said: "O messengers, what is your duty?"
The Rocky Tract/15:58 We have been sent to a guilty people.

The Cattle/6:9 If We had made him an angel, We would have sent him in the form of a man and left him in his present doubts.

The Cave/18:65 They found a servant of our servants to whom We had given mercy from Our Presence and taught him of Our knowledge.
The Cave/18:74 "So they walked on. When they came to a young man, he killed him immediately. He said, "Why did you kill an innocent man who had never killed anyone? You have done a very bad deed."
The Cave/18:78 "He said: "This is the end of my association with you. And I will make known to you the explanation of that which you cannot bear."
The Cave/18:80 As for the child, his parents were two believers. We feared that he would burden them with excesses and ingratitude.