“Priests (including the Pope) receive their ashes on their head rather than their forehead.”
Interesting - do you know why that is?
It used to be that a portion of a priests' hair was cut when he was ordained. This was called the "tonsure". (It was originally a symbol of slavery. From there it spread to monks, meaning that they were slaves of Christ. From monks it spread to priests generally.)
There were different kinds of tonsure. The Roman style shaved the crown of the head, and left a ring of hair around the sides.
Clerics generally received their ashes on their tonsure, not on their forehead.
http://www.freerepublic.com/focus/religion/1966408/posts?page=16#16
Check out this link
Don’t know the exact Biblical references, but sure that sprinkled and ashes would bring it up in a search of a concordance.