I know the title of the topic is really bad because it isn't descriptive, but I don't know how to phrase it really. If you have a better idea please edit it.
What does Yamcha say in this phrase? What I hear is
"Sora na kirei da na" but this doesn't make sense to me, it seems syntactically wrong, I believe for saying "the sky is pretty" it would be something like "sora wa kirei da" or perhaps "sora wa kirei da na" but not what I hear. What is he exactly saying?