The Democratic frontrunner for the presidential nomination quickly seized on her Republican counterpart's comments, tweeting: "Anyone who believes Americans aren't working hard enough hasn't met enough American workers."
She attached a graph showing productivity shooting up over the last several decades while hourly compensation has barely risen.
It's the second attack Clinton has leveled against Bush this week as Clinton is pivoting into the next phase of her campaign and showing she is willing to swipe at the top Republican hopefuls.
Bush later sought to clarify what his remarks -- which he made in an interview with the New Hampshire Union-Leader -- during a town hall event in Hudson, New Hampshire, later on Wednesday, explaining that he was referring to Americans who aren't working full-time.
"You can take it out of context all you want, but high sustained growth means people work 40 hours rather than 30 hours and that by our success they have disposable income for their families to decide how they want to spend it rather than standing in line and being dependent upon government," Bush said.
And early Thursday morning, Bush leveled a comeback at Clinton on Twitter.
"Anyone who discounts 6.5 million people stuck in part-time work & seeking full-time jobs hasnt listened to working Americans @hillaryclinton," Bush tweeted.
Bush's initial remarks came as he was discussing economic growth, saying that he aims to bring the U.S. economy to 4% annual growth.
"(That) means we have to be a lot more productive. Workforce participation has to rise from its all-time modern lows. It means that people need to work longer hours and through their productivity gain more income for their families. That's the only way we are going to get out of this rut that we're in," Bush had said.