When someone greets you with “live long and prosper,” they are telling you to have a good one, and they'll catch you later.
It's a “Vulcan” saying out of the Star Trek franchise, popularized by “Dr. Spock.” Today, many “Trekkies” use the saying when they say goodbye to each other.
'Live long and prosper is an abbreviated version of a traditional Jewish religious blessing.
It came to a wider public in the Star Trek TV series, where it was used there by the character Mr. Spock (actor Leonard Nimoy, himself Jewish) as the greeting of the Vulcan people.
The phrase was the spoken greeting/blessing that accompanied the hand gesture called the Vulcan salute.
'Live long and prosper is translated, if that is the correct word, from the Vulcan language phrase 'dif-tor heh smusma', which was so uttered in Star Trek: The Motion Picture. The phrase echoes the Hebrew 'Shalom Aleichem and the Arabic 'Salaam Alaykum, which roughly translate as 'peace be upon you.
Originally a Jewish saying which was commandeered by the famous television series "Star Trek" when Jewish actor Leonard Nimoy used it as the Vulcan salute. It's now used as a way for us nerds and sci-fi lovers to say goodbye in a different, more permanent way.
The above USA map indicates where exactly in America you may wind up living the longest. Live Long And Prosper: Five Countries Where People Live The Longest https://www.forbes.com/sites/duncanmadden/2022/06/27/live-long-and-pros…