How easy is it for musicians to come up with a verse?

[Kezman]

I just read in the news of a musician in my country who came up with a verse in less than an hour of being in the studio! That's surprising, it goes to show that some do have that talent.
Although I wasn't there when it happened, I'd like to believe it is actually possible.
How fast can musicians come up with a verse in a song they are featured in?

 

[Kennysplash]

It depends on how good the artist is. There are some people that can pull it off in no time, while others need more time. But those that can pull it off easily deserve their respect.