Is it true that the dead visiting in a dream is evidence of their connection to the living?

Ibn al-Qayyim, in "Al-Ruh" (The Soul), discussed the meeting of the souls of the dead with the souls of the living. He cited realistic proofs and narrations from the predecessors (Salaf), among which were instances of a deceased person informing a living person about something the living person did not know, and that information proving to be true. This included informing them about money they had buried or a debt they owed, and he mentioned stories illustrating these points.