Heavyweight world champion Fury (32) had been set to face fellow Briton Anthony Joshua on August 14 in Saudi Arabia in a world heavyweight unification title fight, but an American arbitrator ordered Fury to fight Wilder again before September 15.
Fury first fought Wilder, who is now 35, in 2018 and took the WBC title from him in a rematch in February 2020 with a seventh-round stoppage.
"Shall we do it and put him out of his misery? Crack the other side of his skull? Give him another shoulder injury, another bicep injury, a leg injury... the whole lot," Fury said in a video posted by Top Rank Boxing.
"Wilder, contract's signed, you're getting smashed... You're getting knocked out, end of, one round, you're going. I've got your soul, your mojo, everything, I own you."
The World Boxing Organization (WBO) has ordered Joshua to defend his heavyweight title against mandatory challenger Oleksandr Usyk.
