Jay-Z and Beyonce named their son Sir because of the way the baby "carries himself", and their daughter Rumi is named after the couple's favourite poet.
The famous couple welcomed twins Rumi and Sir Carter into the world in June, and Jay-Z has now revealed that whilst daughter Rumi was named after the pair's favourite poet, Sir's moniker was chosen because of the way he "came out" when he was born.
The 47-year-old rapper - who also has five-year-old daughter Blue Ivy with his spouse - said: "Rumi is our favourite poet, so it was for our daughter. And then Sir was, like, man, come out the gate. He carries himself like that. He just came out, like, Sir."
Jay-Z also admitted that whilst his family will be heading out on tour with him in October, he decided to save touring until later in the year so he could spend quality time with his brood without the pressures of being on the road.
Speaking in the second part of his Rap Radar podcast interview which was published on Friday, the 'Smile' rapper said: "I booked the tour for October so I could have at least four months ... to just really bond and see their fingers and s**t like that. They'll be with me [on tour] anyway, but I'm just saying, like, [I needed] a space where I'm not doing nothing, I'm just focused on them. I'm not thinking about a show at night or anything like that. That's why the tour is so far away from the release of the album."
Meanwhile, it was recently reported that Blue Ivy has been an "amazing" big sister to her two new siblings.
A source said: "Blue is the best big sister. [She] helps Beyoncé every day. Everyone is doing great. They are still enjoying the summer in Malibu. Blue is excited to be back in school soon. The babies are growing and very cute."