Dumbledore Reveals His Fear for Harry's Life
Pages 834-835
Dumbledore reveals to Harry that he distanced himself out of fear for Harry's life. He admits he feared Lord Voldemort would manipulate Harry to spy on him or worse, possess him to destroy Harry in an effort to harm Dumbledore. This was the reason Dumbledore did not teach Harry Occlumency himself and allowed Severus Snape to take over the lessons, although that too proved ineffective.
