“The oxygen caused us immediate physical dependence beause our mother used it during pregnancy. The oxygen-dependents hallucinate obscurely through the mirror, who do not need the material anymore, they see face-to-face. (Source)”

Speech to the American Bar Association (15 July 1985) http://www.margaretthatcher.org/speeches/displaydocument.asp?docid=106096.
See Linda Smith for an amusing variant.
Second term as Prime Minister

This has been widely attributed to Whitman, and no one else, but without definite source. It has sometimes been cited as being from the Brooklyn Daily Eagle (sometimes with a date of 23 July 1846), where Whitman had been an editor, but its presence on that date is not apparent in the online historical archives http://www.brooklynpubliclibrary.org/eagle/ of that publication.
Brian Cronin, in "Did 'Bull Durham' misquote Walt Whitman on baseball?" http://www.latimes.com/sports/sportsnow/la-sp-sn-bull-durham-baseball-20120328,0,5200453.story, Los Angeles Times (28 March 2012), suggests that this is (loosely) paraphrased from a remark of September 1888 reported in Horace L. Traubel, With Walt Whitman in Camden, Vol. 2:
I like your interest in sports ball, chiefest of all base-ball particularly: base-ball is our game: the American game: I connect it with our national character. Sports take people out of doors, get them filled with oxygen generate some of the brutal customs (so-called brutal customs) which, after all, tend to habituate people to a necessary physical stoicism. We are some ways a dyspeptic, nervous set: anything which will repair such losses may be regarded as a blessing to the race. We want to go out and howl, swear, run, jump, wrestle, even fight, if only by so doing we may improve the guts of the people: the guts, vile as guts are, divine as guts are!
"Sports for a Dyspeptic Race", Intimate With Walt: Whitmans Conversataions With Horace Traubel, p. 261 https://books.google.com/books?id=_Rp_4VHeQkAC&printsec=frontcover&dq=With+Walt+Whitman+in+Camden&hl=en&sa=X&ei=dqMtVfHQLcODsAWM-ICIDQ&ved=0CEUQ6AEwBQ#v=onepage&q=base-ball&f=false
Disputed

Source: Unbroken: A World War II Story of Survival, Resilience, and Redemption

Creation seminars (2003-2005), The Garden of Eden

The She-Ancient, in Pt. V
Source: 1920s, Back to Methuselah (1921)
Context: Art is the magic mirror you make to reflect your invisible dreams in visible pictures. You use a glass mirror to see your face: you use works of art to see your soul. But we who are older use neither glass mirrors nor works of art. We have a direct sense of life. When you gain that you will put aside your mirrors and statues, your toys and your dolls.

Context: But if we come under attack, if we face an attempt to take away our country, our freedom, our lives and the lives of our children, we will defend ourselves. When you attack us, you will see our faces. Not our backs, but our faces.