CNN  — 

Speaking in front of hundreds at a rally in South Carolina on Tuesday, Donald Trump read a number he said people could use to reach South Carolina Sen. Lindsey Graham’s private cell phone.

Trump and Graham have engaged in an ongoing feud in the past few days as they battle for the Republican presidential nomination. In Trump’s speech Tuesday, he called Graham an “idiot,” after Graham called him a “jackass,” in an interview Monday with CNN’s Kate Bolduan.

Trump gave out the number and urged attendees to call it.

“Give it a shot,” Trump said, urging people to call the state’s senior senator.