If a deceased person appears in a dream and speaks, is what he says considered to be true?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Please note that not all dreams that a person has in his sleep are true. As a matter of fact, some dreams may be the result of Satanic tampering. This also includes seeing dead people and talking to them during sleep.

Allaah Knows best.