The sentences sound feasible to my ear.
The only thing that caught my attention was the use of 'in time.'
You must come here in time.
He said you must come here in time.
In AmE, 'in time' is usually followed by more information:
You must come here in time to catch the bus.
Generally, Americans would say, You must come here on time.
I hope this is helpful,
Student or Learner