From an article by Matthew Jacobs on the Huff Post:

Madonna is moving swiftly through her Rebel Heart tracklist, releasing Living for Love and Ghosttown videos and performing Joan of Arc, Devil Pray and, most recently, Bitch I’m Madonna. She debuted the latter on The Tonight Show Starring Jimmy Fallon last week, during which Diplo joined her for a rowdy performance that found Madonna and her dancers prancing through the entire studio.

Bitch I’m Madonna, which Diplo produced alongside English electronic producer Sophie, is among the six songs Madonna rushed to release after Rebel Heart leaked online in December. When The Huffington Post sat down with her last month, we asked Madonna to recount an instance where she used the expression “bitch, I’m Madonna” — but the singer insisted the thought hadn’t entered her mind until Diplo introduced it to her. The song’s title might sound like a puffed-up self-reference, but Diplo told us this week, while promoting Major Lazer’s new self-titled animated series, that the expression isn’t unique to Madonna. In other words, anyone who maintains his or her cool in the face of boundless criticism is, in effect, a Madonna.

Diplo couldn’t recall the exact origins of the idea of “being Madonna,” but he knows he heard it in a rap song, perhaps by Lil B, whose Pretty Boy Anthem includes the lyrics “I look like Madonna / Bitch, I’m a farmer.” He took the idea to Madonna herself, insisting they recruit Nicki Minaj, who collaborated on Madonna’s Give Me All Your Luvin’ and has long been vocal about idolizing the 56-year-old singer. Diplo said the song addresses naysayers who slam Madonna because she’s been in the business for so long – just like those who used her age as ridicule for making out with Drake during his recent Coachella set, a moment Diplo praised as “sick.”

Diplo explains, making clear why the Tonight Show performance featured Madonna’s son Rocco, an actor dressed as a police officer and even Fallon himself saying the words “bitch, I’m Madonna:”

We made this record about, ‘Fuck it, bitch, we’re all Madonna.

That means it can be your catchphrase, too.