It is not clear why the sight of Samuel caused the woman to recognize that her client was Saul. Her client had already told her that he was looking for Samuel. Perhaps as the spirit appeared, she may have heard it call Saul by name.1 Alternatively, if the spirits normally spoke without any visual appearance, the appearance of Samuel made her realize that her client was especially important and therefore must have been Saul.2
12 When the woman saw Samuel, she cried out with a loud voice. And the woman said to Saul, “Why have you deceived me? You are Saul.”