1
general::
Phrase(s): one and the same
Cliché the very same person or thing. • John Jones and J. Jones are one and the same. • Men’s socks and men’s stockings are almost one and the same.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
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]
American Heritage Idioms