。
Get up at 7 tomorrow morning.
Literal
Tomorrow [possessive-の] morning [topic-は] 7-o'clock [at-に] get-up.
Simple なさい command for a specific clock time. Note は on 明日の朝 — the topic marker, setting up 'tomorrow morning' as the framing context for the command that follows. The は makes the time expression a topical frame rather than a bare adverbial.