Eminem waited to present Beyonce with the perfect collaboration idea, because he knew she'd reject anything that wasn't an instant hit for her.

The rapper, who has scaled pop charts with Rihanna and Dido in the past, recently teamed up with the new mum in the studio for Walk On Water, and he now reveals he knew the track would lure in the R&B superstar.

"It’s been on my wish list for a long time, but I never really had a song that I felt like would be right to present to her," Eminem told DJ Whoo Kid and Lord Sear during a taped SiriusXM Shade 45 radio chat on Friday (17Nov17), "and based off what it was about, I felt like she probably could relate to this, too."

Walk on Water is the first song from the Lose Yourself hitmaker's rumoured new album, which is reportedly called Revival.

The track was released last week, days after Eminem teased the single by writing "Walk on Water" on a fake prescription card and sharing it online.

The song kicks off with the Drunk in Love star singing, "I walk on water, but I ain't no Jesus/I walk on water but only when it freezes," and she later adds, "'Cause I'm only human, just like you/Making my mistakes, oh if you only knew/I don't think you should believe in me the way that you do/Because I'm terrified to let you down."

In his verses, Eminem raps about his career and his fears of not living up to his fans' expectations.

Eminem didn't elaborate on the meaning behind the new song, but added, "Everything she does is so perfect, but the pressures behind that... for her to do it so perfect, you know, I felt like she could probably relate to that.

"I told her, 'I never seen you make a mistake before, ever'. Like, performance-wise, everything. Every song she puts out, every album, it’s so calculated and precise. And everything’s always so perfect."