When exactly was this stated? If I'm thinking of the same thing, I thought it was the Rasenshuriken that he could throw and expand...
It was in the beginning if I'm not mistake, when Naruto returns to the village after his training and Jiraiya leaves to get more info on the Akatski then he turns to Naruto and says, "Oh and Naruto, don't use "That Jutsu". Something like that, I think it was from Chapter 251