A Stash from the Past was the fourth episode of Season 6 of Roseanne, also the 126th overall series episode. It was written by Kevin Abbott and was directed by Philip Charles MacKenzie. It originally aired on ABC-TV on October 5, 1993.
Roseanne, shocked to find a bag of marijuana in David's room, immediately punishes him for possession. David thinks it's Darlene's, so he covers for her by saying it's his. But Dan realizes that it's a 20-year-old stash of his and Roseanne's, so they and Jackie indulge once again for old times' sake...
One of the most memorable episodes of the series, "A Stash From the Past" is the one where Dan and Roseanne get high. Dan is having troubles at work while Roseanne is mad at David (Johnny Galecki) when she finds a bag of pot in the house. It turns out to be her bag that she lost years ago.