Beyoncé Jay Z

Jay Z and Beyonce at the 59th annual Grammy Awards in Los Angeles, California, February 2017.

Kevin Mazur/Getty Images

Throughout the press cycle for his new album, 4:44, Jay-Z has been dropping little truth bombs here and there, whether through his own music videos (Tidal exclusives, naturally) or in various interviews. For example, in a video he called “Footnotes for 4:44,” released last month, the rapper appeared alongside peers like Kendrick Lamar, Will Smith, Mahershala Ali, and others to discuss toxic masculinity—the perfect entry point for Jay-Z to continue unpacking his infidelity.

“I just ran into this place and we built this big, beautiful mansion of a relationship that wasn’t totally built on the 100 percent truth and it starts cracking,” he said. “Things start happening that the public can see.”

The rapper’s latest revelation is perhaps a little less salacious, but still a necessary document for the average Bey-ologist. Beyoncé gave birth to twins earlier in the summer, prompting speculation of a burgeoning Carter-Knowles supergroup. Their names, as the couple announced shortly after: Sir and Rumi.

Now, in case anyone was wondering, Jay-Z has finally illuminated the meaning behind the names. He went on the podcast Rap Radar to discuss everything from his relationship with Kanye West to the elevator tiff with Beyoncé’s sister Solange and how his new album came to be—and how he and Beyoncé selected the names for the twins. Their infant daughter Rumi was named for their “favorite poet,” the 13th-century Persian lyricist, while their son Sir’s name was, well, more a matter of swagger: “Sir was like, man, come out the gate,” Jay-Z said on Rap Radar. “He carries himself like that. He just came out, like, Sir.”

Rumi is not the first time the Carter-Knowles have sought inspiration in literature. Several months after Blue Ivy’s birth in 2012, Beyoncé posted an excerpt from Rebecca Solnit’s essay collection A Field Guide to Getting Lost on her Tumblr, alluding to the significance of the color blue. “The world is blue at its edges and in its depths. This blue is the light that got lost,” it reads. “Water is colorless, shallow water appears to be the color of whatever lies underneath it, but deep water is full of this scattered light, the purer the water the deeper the blue. The sky is blue for the same reason, but the blue at the horizon, the blue of the land that seems to be dissolving into the sky, is a deeper, dreamier, melancholy blue, the blue at the farthest reaches of the places where you see for miles, the blue of distance. This light does not touch us, does not travel the whole distance, the light that gets lost, gives us the beauty of the world, so much of which is in the color blue.”

Some have speculated "Ivy" represents the Roman numeral IV, which has particular meaning for both Beyoncé and Jay-Z, who were born on the fourth of September and December, respectively, and married on the fourth of April. Plus, Jay-Z named his record 4:44, and Beyoncé titled her fourth album, simply, 4.

So, the origins of Sir and Rumi look positively straightforward next to the mysticism and symbolism behind Blue Ivy’s name. The perks of being the first child.

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