"I tell you, I am going to do my very best to communicate as clearly and as fearlessly as I can in the face of the insults and the attacks and the bullying and bigotry we've seen coming from my opponent," Clinton said.
"You know I can take it," she said. "I can take that kind of stuff."
Clinton said her health is fine after taking three days off from campaigning last week to recover from what her doctor said was a mild case of pneumonia, and she said her two grandchildren "are the best thing in my life by such a country mile."
Shortly after she called in to the radio program, Trump taunted her on Twitter.
"Hillary Clinton is taking the day off again, she needs the rest. Sleep well Hillary — see you at the debate!" Trump said.
Clinton's campaign has refused to say much about how she is preparing for the debate, which will pit her face to face against the Republican businessman who calls her "Crooked Hillary." For instance, it remains a mystery who is playing Trump in any mock debates that Clinton is holding. Her campaign said the role might be filled by more than one person at different times.
As she has before, Clinton said she objects to what Trump says about others. She said she is "appalled" that Trump has not apologized for questioning President Obama's birthplace and thus his legitimacy to be president, now that Trump has disavowed the theory that Obama was born outside the United States.
"I'm not going to take what he says about everybody else," Clinton said. "His attacks on African Americans and immigrants and Muslims and women and people with disabilities. It's just something we cannot tolerate."
Clinton made a pitch for the mostly African American audience to vote Nov. 8.
"They cannot stay on the sidelines," Clinton said. "Every issue they care about is at stake in this election."