He watches Daniel wake, slowly and reluctantly; he doesn't see the appeal of sleep, personally. It hasn't been pleasant for him any time it happened, and it honestly doesn't look pleasant for Daniel, either. And he snores, too. It's very undignified.

Daniel barely stays on the bed after he notices Lucifer's presence across from him, and the Devil cocks his head at the awkward position he's twisted himself into. Nothing surprising here, Satan is exactly where you left him. And, if it would make him feel any better, it's perfectly possible that he slept-- perhaps he's just an early riser. A very early riser.

"Good morning," he says, because he's fairly certain that's the common greeting.