Blake Shelton says he wrote a song for Gwen Stefani as part of his wedding vows

Blake Shelton revealed he penned and composed a song for Gwen Stefani as vows during stunning wedding with her.

The country singer tied the knot on July 3 on his Oklahoma estate.

The couple knew they were writing their vows because Carson Daly, who officiated the ceremony, asked them to.

In a rare interview with PEOPLE, Shelton revealed he surprised his ladylove with a song he wrote for her named, "We Can Reach the Stars," However, Stefani's words to him took his breath away, he said.

"She took that really hard, took it to heart and talked about it all the time," Shelton said. "She was like, "Oh my God, I'm still working on it.'"

When she read them to him during their ceremony, he understood why.

"The thing that got to me was she spoke about my [late] brother and my dad as if she had known them almost," Shelton explained.

"She didn't make it seem that way, but it felt that way as she was speaking about them. She said she wished they were there and what kind of men she thinks they must've been.

"Man, it hit me. Like, I couldn't believe how hard it hit me. I felt like at this point, I've kind of gotten calloused. I guess I'm not because that absolutely slayed me. It's hard to even remember what else she even said. I'll never forget that feeling," he added.

Shelton took writing his vows just as seriously. He chose to write her a song because he said it was the last thing she would expect.

"For me, writing songs is like going to the dentist sometimes," Shelton admitted. So the fact that I did that, I think it was a complete shock to her."

"Everything happened exactly how it was meant to happen," the country singer further said. "It just like, 'Wow, we did it. I have a song about my wife.' It was so exciting to me."