[quack!]

you counted 17 white hair on our beloved prophet Muhammad SAW's beard... This seems about right as the narrations state that he had around 20 white hair altogether, some say a bit more, some say a bit less.... so definitely inshallah you saw our beloved in the dream....may ALLAH guide us all....do pray also that I get a chance to see the beloved......carry on reading the verses that allowed u to see the dream...there are some ashiqs who would sacrifice everything to get 1 glimpse at the prophet SAW so you are very lucky....This is the blessings of durood usually...