Can dreams come true? And is it true that a deceased person's visit to their family in a dream might signify the death of one of them, especially since the deceased father visited his son in a dream a short while before his granddaughter's death?

If a person sees something he dislikes in his dream, he should spit to his left and seek refuge in Allah from Satan, for it will not harm him, and he should not tell anyone about it. The dream may or may not come true. A deceased person visiting his family in a dream does not necessarily mean that one of them will die.