President Trump pushed back on former FBI Director James Comey's explanation for a recent social media post that appeared to call for a hit on the president's life, saying, "He knew exactly what that meant."

Comey has since deleted the Instagram post he shared Thursday that showed the numbers "86 47" etched in the sand at a beach via seashells. The numbers are perceived as a call to "86" the 47th president, which is used as a call sign for murder. And he attempted to walk back the post, which he originally captioned "Cool shell formation on my beach walk," by stating he was unaware of the violent message behind the numbers. 

"I posted earlier a picture of some shells I saw today on a beach walk, which I assumed were a political message," Comey's follow-up post read on Thursday. "I didn't realize some folks associate those numbers with violence. It never occurred to me but I oppose violence of any kind so I took the post down."

In a preview of a Fox News interview to be aired Friday night and posted on social media, Trump called out Comey's explanation.

"He knew exactly what that meant. A child knows what that meant," Trump said. "If you're the FBI director and you don't know what that meant? That meant assassination. And it says it loud and clear. Now, he wasn't very competent, but he was competent enough to know what that meant. And he did it for a reason, and he was hit so hard, because people like me, and they like what's happening with our country. Our country has become respected again and all this -- and he's calling for the assassination of the president."

"I don't want to take a position on it because that's going to be up to Pam [Bondi] and all of the great people," Trump added. "But I will say this, I think it's a terrible thing, and when you add his history to that, if he had a clean history -- he doesn't, he's a dirty cop. He's a dirty cop. And if he had a clean history, I could understand if there was a leniency. But I'm going let them make that decision."

Homeland Security Secretary Kristi Noem on Thursday evening confirmed that the Secret Service and her department are investigating the post.