one and the same
Identical, as in Gloria's grandfather had been, at one and the same time, a physician at the court and a general in the army. This expression is an emphatic form of “the same.” [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
Examples from the Web for one and the same
Mom and daughter are often referred to as one-and-the-same (as in “They like...”) and work hand in glove together.America's New Sweetheart
June 1, 2010