Carrie Underwood's first-ever holiday album, My Gift, got a boost from an extra-special guest when it was released back in September: The singer's 5-year-old son, Isaiah, duets with his mama on a rendition of "Little Drummer Boy."

Underwood has previously shared what an incredible experience it was to be in the vocal booth with her son, and how proud she is of his participation in the track. But in a new article in Guideposts, the singer reveals the sweet way that Isaiah showed how important the duet was to him, too.

The day that they went in to record the song, Underwood remembers that Isaiah dressed sharply for the occasion.

"He came down the stairs in his jeans he wears to church, a button-down shirt and a little black fedora," she says, adding that when she remarked to Isaiah how nice he looked, his response melted her heart.

"I'm gonna go sing for Jesus," he explained, "So I wanted to look nice."

It was a powerful sentiment for the singer, whose commitment to faith is such a large part of her life that both her children have Biblical names. In fact, the title of My Gift comes from one of the lyrics of "Little Drummer Boy" and ties directly into the foundation of faith that is such an important part of the holiday season to Underwood and her family.

"Bringing out best to Jesus — we can all do that," Underwood reflects in her article, explaining how Isaiah's outfit selection offered a reminder of the powerful meaning behind the song they were going in to record.

"What talent, passion or treasure makes you who you are? It might seem small, like that baby in a manger, or insignificant, like a boy playing a drum," she adds. "But you never know until you share your gift, a gift that can help shine love's pure light on the whole world this Christmas."

Fans can get a peek into the Isaiah and Underwood's recording process with the release of her My Gift: A Christmas Special From Carrie Underwood holiday television show, which will be available to watch on HBO Max beginning Dec. 3. In addition to Isaiah, another mega-watt duet partner, John Legend, also makes an appearance in the special.

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