There was a something special about the two-run home run by David Ortiz on Friday night, and not just because it helped the Boston Red Sox beat the New York Yankees, 4-2.

Ortiz, the power hitter who has announced he will retire after the season, made a video with former teammate Kevin Millar and in it shared a promise to a sick child that he would hit a home run.

After the game Millar, now an analyst for MLB Network, shared a series of posts on Twitter (@KMillar15) about the story behind the home run. He first shared a picture of a young boy named Maverick, who he says “battles for his life daily and is a big Red Sox fan.” He then posted a video he and Ortiz sent to Maverick before the game.

“Always stay positive, keep the faith,” Ortiz (@davidortiz) said in the video. “You take care buddy. And I am going to hit a home run for you tonight.”

Millar also posted a response from Maverick from after the game.

“Big Papi you never let me down,” Maverick said. “You are the best player ever in the Red Sox game. And I’m trying the hardest to get out there at Fenway Park and meet you.”

On Friday night against the Yankees with the game tied 2-2 and Xander Bogaerts on base in the bottom of the eighth, Ortiz turned on a curve ball and delivered the home run, rounding the bases and hugging Millar’s children on his way back to the dugout.