According to Urban Dictionary Yoda says, “The Fuck Shut Up” (T.F.S.U.) in place of “Shut The Fuck Up” (S.T.F.U).
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How would the Jedi Master say “Harden The Fuck Up” (H.T.F.U.)? I can envision him saying this to Luke Skywalker when Luke is acting like a panzee in the swamp when he is trying to levitate his X-Wing fighter.