The song begins with Balvin saying hello to his yet-unborn son, crooning in Spanish, "You came to give me light. I dreamed of you long ago when I least expected it."
"Querido, Río, llegaste en el momento debido/Aún no estás en mis brazos, pero ya te siento mío," he sings in the chorus, which translates to, "Dear Rio, you came at the right now. You're not in my arms yet, but I can already feel you."
He also sings, "En este beat puse tu corazón," which means, "in this beat I put your heart," as well as tells his son that he will always be there for him and hopes to be his best friend.
On Thursday, he seemingly posted a photo of his son, wearing a onesie with his album tracklist. He wrote "Querido Rio" on the photo.
Balvin confirmed that he used Rio's heartbeat, recorded during an ultrasound, in an interview with Billboard. He also expressed how emotional it was to create the song.
"I had never cried so hard making a song. I had to take pauses between takes. I wrote it before Rio was born [this past June], but I wouldn’t change a thing," he told the magazine.
Balvin previously told ET his hopes for fatherhood and reflected on whether he plans on being a fun dad or a strict dad.
"I'm gonna be his best friend!" Balvin said with a smile. "That's what I want to be, yeah."
"And sometimes, we know life is so challenging that sometimes you feel that you cannot put up with yourself and how [are] you going to help your kid be stronger, better than you?" he continued. "But I think that will come. But let's see, it's something new for me. Totally new."
Up next for Balvin is a tour. The new dad announced the dates for his 2022 U.S., Canada and Puerto Rico Jose tour. Concerts will kick off April 19 in San Antonio, Texas, and wrap June 4 in Puerto Rico.