"I am not from the wizarding world. You are from an older pureblooded family that was active in the first war. The Weasleys were present when Sirius Black was dragged screaming through the Ministry to Azkaban. If you are the one to tell him, he will wonder, why you did not tell him before. If I do it, I can simply tell him that I read some of the newspapers printed during the times of the war while searching for any mention on Nicholas Flamel."