In widely circulated remarks, Jimmy Carter, the longest-living president in United States history, weighed in on a range of issues, including the appropriate age for a commander in chief, Democrats’ 2020 prospects and the relative merits of various nut products.

Perhaps most memorably, Mr. Carter, speaking two weeks before his 95th birthday at the Carter Center in Atlanta, suggested a possible candidacy restriction when asked whether he would consider running for a second term as president.

“I hope there’s an age limit,” Mr. Carter said to laughter at the event on Sept. 17, billed as a conversation with his wife, Rosalynn Carter, the former first lady.

There are currently five candidates seeking the presidency in 2020 who are at least 70, including the three Democratic front-runners, former Vice President Joseph R. Biden Jr. (76), Senator Elizabeth Warren (70) and Senator Bernie Sanders (77). President Trump is 73.