Damar Hamlin, the Buffalo Bills defensive back who went into cardiac arrest during a “Monday Night Football” game on Jan. 2 and narrowly avoided death thanks to a swift medical response, spoke publicly for the first time since his on-field collapse shocked millions of viewers.

In a video posted on social media on Saturday night, Hamlin, who was discharged from a Buffalo hospital on Jan. 11, said that he had waited until the Bills had finished their season and until he had made further progress in his recovery to speak. “It was just a lot to process within my own self, mentally, physically, even spiritually,” he said.

In the video, Hamlin said he was thankful that his medical emergency had unexpectedly provided him with an opportunity to make a difference.

“What happened to me on ‘Monday Night Football,’ I feel, is a direct example of God using me as a vessel to share my passion and my love directly from my heart with the entire world,” he said. “And I’m able to give it back to kids and communities all across the world who need it the most, and that’s always been my dream. That’s always been what I stood for and what I will continue to stand for.”

He offered no details on his condition, but he appeared to be speaking and walking without issue, and Hamlin’s doctors have said he has shown no signs of neurological deficits. Hamlin has posted on social media over the last three weeks, but this was the first time since his hospitalization that he had spoken to the public on camera.

Hamlin’s medical emergency, which occurred during the first quarter of a game against the Cincinnati Bengals, led to an outpouring of support. More than 200,000 people donated more than $9 million to a toy drive Hamlin had previously established on a GoFundMe page. A representative for Hamlin has said the money will go to Hamlin’s charitable foundation.

Hamlin, 24, made what appeared to be a routine tackle in the game in Cincinnati in early January, after which he stood up briefly and then collapsed to the turf. As it became apparent that Hamlin’s condition was dire, doctors, athletic trainers and emergency personnel worked to save his life. He received CPR and was rushed to a Cincinnati hospital, where he spent nearly a week in the intensive care unit. He was later transported to a hospital in Buffalo.

Dr. Timothy A. Pritts, the chief of the section of general surgery at the University of Cincinnati Medical Center, where Hamlin was treated, has said that Hamlin “was dead” when he fell to the ground. The swift response by medical personnel helped save Hamlin’s life during his cardiac arrest, a condition in which every minute counts.

In the video, which is nearly six minutes long, Hamlin rattled off a long list of thanks for the medical staff who had treated him, naming at least 20 doctors and other professionals from the Bills staff and the hospitals in Cincinnati and Buffalo. He also thanked his family, fellow players, Bills fans, the Bengals, the N.F.L. and children who had sent him letters of support.

The game between the Bills and the Bengals was initially suspended before being canceled entirely. The teams met again last Sunday in the divisional round of the playoffs, a game the Bengals won, 27-10, ending the Bills’ season in a defeat at home with Hamlin in attendance. Cincinnati will play Kansas City on Sunday in the A.F.C. championship game, and the winner will advance to the Super Bowl.