"She's always been very, very healthy and she has very low blood pressure, very low standing heartbeat," Clinton said in a video of the event posted on the Telegraph. "I tell her that, you know, she's still got time to have three more husbands after me. So I think she'll live to be 120."
The former president continued to riff, saying his wife "refers to me as her first husband."
At an event with reporters last week, Clinton said she was "back in the swing."
"I am thrilled to be back and I am also incredibly grateful for this fabulous team that I have here at the State Department who never missed a beat during the time I was away," Clinton said.
Clinton will be stepping away from the department in the coming weeks, with Sen. John Kerry (D-Mass.) nominated to replace her. But speculation is rampant that she will contend for the Democratic presidential nominee in 2016.
In his comments, her husband hinted at the potential of a re-emergence in public life.
"My advice is that she should rest up and decide what she wants to do with the rest of her life," Clinton said.