This is an instance of a dream of exact physical prevision. The power to have such dreams is comparatively rare, for ordinarily such previsions come in inner vision but not in sleep. In dreams vital or mental formations often take shape which sometimes fulfil themselves in essence, but not with accuracy of detail.

It is only a particular class of dreams that do that (indicate the exact past and the future). Most coherent dreams are either symbolic or indicate things that take place in the mental or vital planes rather than on the physical.

This indicates a power of conscious-formation. Thoughts have an effective power, usually by creating an atmosphere or tendencies, thus when one is ill, those around should not have thoughts of gloomy foreboding, grief or thought-formation is a special power and uncommon. It can be acquired or come of itself by sadhana.