(Photo Credit: Kevin Winter/Getty Images)

Steve Martin felt compelled to explain his offensive tweet from this past weekend.

On Friday night, the actor asked his Twitter followers to "submit your grammar here," and when one user asked, "Is this how you spell lasonia?" Martin responded, "It depends. Are you in an African-American neighborhood or at an Italian restaurant?"

Yesterday, the comedian posted on his website "I am very upset that a tweet I sent out last week has been interpreted by some to be insulting to African Americans … To those who were offended, again, I offer a deep, sincere, and humble apology without reservation."

Martin, 68, had already apologized via Twitter for the "offensive thing I'd done."

Read: Steve Martin Apologizes for 'Offensive' Tweet

But Martin further explained that his "grammar" session with fans is something he's done on other occasions, like "For example, a person might write 'What's the difference between 'then' and 'than?' I would say, 'then' is a conjunctive preposition, and 'than' is a misspelling of 'thank.'"

The "Father of the Bride" star continued, "I was going along fine when someone wrote, "How do you spell 'lasonia?' I wrote: 'It depends if you are in an African American neighborhood or an Italian restaurant.' I knew of the name Lasonia. I did not make it up, nor do I find it funny. So to me the answer was either Lasonia (with a capital), or Lasagna, depending on what you meant."

"That they sounded alike in this rare and particular context struck me as funny. That was the joke. When the tweet went out, I saw some negative comments and immediately deleted the tweet and apologized. I gathered the perception was that I was making fun of African American names. Later, thinking it over, I realized the tweet was irresponsible, and made a fuller apology on Twitter," he added.

Related: Steve Martin and Other Celeb Twitter Gaffes

Martin added that he was cited incorrectly by some media outlets, who have yet to correct their misquoting of his tweet.

But in the end, he again took responsibility for the blunder.

"Comedy is treacherous. I used to try out jokes in clubs and the audience's feedback would tell me when I had crossed a line, or how to shape a joke so it is clear," he said. "Today, the process is faster. It's your brain, a button, then millions of reactions. But it's my job to know."