"Your mother," Snape declared in withering tones, "is hardly an expert on anything to do with the mind.
And frankly, neither are Muggles. They don't even know Obliviation, or Legilimency, or Occlumency, or any of the Mental Arts even exist. I never thought it was a good idea to let you see that silly Muggle-obsessed bint.
Now," he said in gentler tones, as he thrust out an open hand for the book in a no-nonsense manner, "Let me see."