someone appealed to me for help from a distant land, claiming that he had seen me arrive. One of them said, “I saw you riding, dressed exactly as you do and in your very likeness.” Another said, “I saw you on a mountain,” and others reported different visions. I told them that I had not helped them at all; it was only a devil who had assumed my form in order to lead them astray once they committed shirk against Allah by calling upon someone other than Him.
In the same way, more than one of the companions I personally know has had a similar experience: a person who thought well of him called upon him, then saw him come and fulfill his need. My companion later said, “I knew nothing about it.” Among these shaykhs are some who claim that they hear the voice of the person imploring them and that they answer him. In reality, the devils make them hear a sound that resembles the voice of the shaykh being invoked; the shaykh replies in his own voice, and then the devils make the supplicant hear a sound resembling that same voice, so he thinks it is truly the shaykh speaking.
This happened to someone I know; he related the incident himself and said, “He remained—”