First lady Michelle Obama took a not-so-subtle dig at presumptive Republican nominee Donald Trump during her commencement address at City College in New York on Friday.

Obama never mentioned Trump's name, but she emphasized to graduates the merits of unity, as she said, "We're all in this together" -- a phrase the businessman has trotted out a few times, though with not as much meaning.

"And here in America, we don't give into our fears. We don't build up walls to keep people out, because we know that our greatness has always depended on contributions from people who were born elsewhere but sought out this country and made it our home," she said. "Some folks out there seem to have a very different perspective."

She continued: "They seem to view our diversity as a threat to be contained rather than as a resource to be tapped. They tell us to be afraid of those who are different. To be suspicious of those with whom we disagree. They act as if name-calling is an acceptable substitute for thoughtful debate as if anger and intolerance should be our default state rather than the optimism and openness that have always been the engine of our progress."

Obama joined a growing chorus of commencement speakers who have taken advantage of their audience to throw shade at Trump. President Barack Obama, Sen. Elizabeth Warren (D-Mass.), Secretary of State John Kerry, 2012 GOP presidential candidate Mitt Romney and "Hamilton" creator Lin-Manuel Miranda all had similar messages urging graduates to be wary of Trump.

“When our leaders express a disdain for facts, when they’re not held accountable for repeating falsehoods, and just making stuff up while actual experts are dismissed as elitist, then we’ve got a problem. The rejection of facts, the rejection of reason and science, that is the path to decline," the president told graduates at Rutgers University.

Read more from the first lady's speech here.