Jimmy Fallon was serious for a few minutes on Monday night’s episode of The Tonight Show. He wanted to honor David Letterman, who is signing off from his Late Show on Wednesday night.

CBS News reports that Jimmy Fallon even got a little teary-eyed when lauding the man who–for more than a year–was his biggest TV competition.

“I, like every kid who grew up watching him, will miss him,” Fallon said, noting that one of his teachers once told him he was going to grow up and replace David Letterman.

The most serious aspect of Jimmy Fallon’s tribute came as he recalled David Letterman’s words during The Late Show’s first night back on the air following the terrorist attacks on 9/11.

How David Letterman changed the late-night landscape http://t.co/vdicdy00gl pic.twitter.com/7lFQqlpxgS

— Bloomberg Business (@business) May 19, 2015

“The city was in shock, and we’re all looking for answers, and we wanted to see what Dave had to say and we looked at him to say something,” Fallon told his audience. “He said, ‘There’s only one requirement for any of us, and that’s to be courageous, because courage, as you might know, defines all other human behavior.'”

“David Letterman is courageous,” Jimmy Fallon added. “Have a nice retirement, Dave!”

If you missed The Tonight Show With Jimmy Fallon on Monday night, check out Fallon’s tribute to David Letterman below.

David Letterman’s last official guest will be Bill Murray on Tuesday night. Wednesday’s show will feature several network surprises as Letterman signs off for good after more than three decades on TV.