The forward was talking to TV4 in Sweden when asked what the result of the qualifier would be, and at first Ibra's response was suitably neutral.
That quickly changed.
TV4 reporter—"Who'll win the qualifier?" Ibrahimović—"Only God knows" Reporter—"It's kinda hard to ask him" Ibra—"You're talking to him now"— Nik Postinger (@nikpostinger) November 15, 2013
Of course, context is everything, and it would appear that Zlatan was being humorous rather than serious with the reporter.
Another journalist reporting the quote adds a laugh at the end to indicate the same:
Ibra: ”Only God knows.” Reporter at TV4 (@ekwall): ”Well, it's kinda hard to ask him.” Ibra: ”You're talking to him now hehe.”— Johanna Garå (@johannagara) November 15, 2013
Even if Ibra was joking, it takes a certain kind of person to be able to make that joke. Tongue-in-cheek or not, you won't be hearing Johan Elmander cracking that gag before the match.
Cristiano Ronaldo? Maybe.