Instagram | @therock

Dwayne Johnson Sings 'Moana' Song To 3-Year-Old Boy Battling Cancer

Y'all ready to cry? Because I'm already crying.

The Rock made a video for Hyrum Harris, a 3-year old boy battling cancer. And I do not have to tell you how precious that is, because you already know. Hyrum also needs all of our help in his battle, so let's rally together to help him out!

The Rock found out about Hyrum via a friend.

GoFundMe | April Harris

According to him, his friend, Andy Fickman, saw Hyrum's story online.

He immediately texted the Rock, who decided to make a video to help cheer Hyrum up and encourage him to keep fighting.

He knew exactly what Hyrum is up against.

Instagram | @therock

"There's a little 3-year-old boy out there named Hyrum Harris. Diagnosed with acute lymphoblastic leukemia which is complicated by Down Syndrome."

According to his mom, he had a 30% chance of developing that cancer because of his Down Syndrome.

Hyrum is a huge "Moana" fan.

"In the fight of his life right now and doing his best to stay strong - by watching MOANA up to 10xs a day because the character he loves, MAUI makes him feel strong."

He has a special mantra.

Instagram | @therock

"According to Hyrum’s mama, his most important thing to say now is, 'I STRONG'. Yes you are big man. Yes you are."

His mom also said that he suffers from Epilepsy, Asthma, Chronic Croup, FPIES, as well as cancer.

The Rock also made some sweet jokes.

Instagram | @therock

"Hyrum, I know I’m a complete stranger to you - who sounds a lot like your hero, MAUI (only with a very large head), but myself along with millions of other strangers who will watch this video are sending you so much love, strength and mana your way. "

And he used Hyrum's mantra.

GoFundMe | April Harris

"I STRONG. Love, the Rock aka the dude who sounds a lot like Maui."

Hyrum was diagnosed with leukemia on October 20th. His family has created a hashtag for him: #hopeforHyrum.

In the video, the Rock pretended he wasn't Maui...

...but that he was also a fan of Maui.

"I know a little bit of his song," he said "and the part that I know, it goes like this — you probably know it better than I do..."

And then he sang all of "You're Welcome" from the film.

Hyrum's mom was over the moon.

According to a Facebook post, April Harris, Hyrum's mom, loved the video.

She showed it to Hyrum, who laughed and pointed to himself every time the Rock said his name.

The video helped more than just Hyrum.

Instagram | @therock

It lifted the spirits of everyone at the hospital who saw it.

It also gave their family a boost.

"[...] if they need a little help, they can borrow strength from The Rock."

More celebrities joined in to support Hyrum.

Instagram | @therock

Ryan Reynolds commented, "This is the good work, D."

Surprisingly, Hyrum's mom responded to that comment. Her Instagram is full of stories about Hyrum's difficult journey, as well as the trials she faces as the parent of a sick child.

His mom thanked him.

Instagram | @pr3ttylittleladies

She wrote, "@vancityreynolds thank you for your comment. My family is going crazy over your comment... Hyrum may not know who you are but the rest of the family say hi!"

Their family has gone viral overnight.

They've been interviewed by multiple outlets about Hyrum's story, including CBS News and Good Morning America.

"Who would have known that a very real moment from a stranger would have had so much impact on our nation," she wrote.

She posted a picture of Hyrum watching his special video.

She revealed that the Rock sent the video to them privately at first, and then shared it on social media a while later.

"Thank you for loving my boy and praying for him and our family to have strength. It was a good day to have strength."

Hyrum has a long road ahead of him.

His mom shares updates about sweet Hyrum frequently. He recently finished stage 1 of his treatment, which means their family can go home for a little while.

However, he still has a lot left to conquer.

You can support Hyrum and his family, too.

Healthcare is expensive, and Hyrum's fight won't be easy. His mom started a GoFundMe to help cover the expenses of his treatment.

You can donate to help their family right here.