The 62-year-old star was a guest on Late Night with Jimmy Fallon when the subject of his unused Twitter page came up and he revealed he was about to post his first tweet.
He said: 'I am joining the electronic age. I am officially launching my Twitter site. I have zero followers, I am in a race to see how long it's gonna take me to get to a million so I catch up with you.'
He then posted the rude message on his page and Fallon said: 'You can't post that on TV!'
Jackson had posted a number of photos online during the show before writing the message: 'Can-a muh f****say f*** on here?'
He added: 'Excellent, so I can tell people now I'm over at the Shake Shack getting a burger!'