What is the wisdom behind Allah sending the angel, despite His prior knowledge of the news the angel will bring?

The two hadiths refer to the succession of angels over the children of Adam by night and day, and their gathering during the Fajr and Asr prayers. Allah—He is most knowing—asks them about the state of His servants, and they reply that they left them and came to them while they were praying. Similarly, there are angels who roam, seeking out the people of remembrance. When they find a group remembering Allah, they encompass them with their wings. Their Lord—He is most knowing—asks them what His servants are saying, and they reply that they are glorifying, exalting, and praising Him. The wisdom behind this questioning is to invoke the angels' testimony to the goodness of the children of Adam and to demonstrate the wisdom in the creation of man, or it is a question by way of the angels' worship.