
First/last thing
Time Specific
The phrase marks a specific routine time; it's about when something happens rather than what or how.
She reads the newspaper first thing every morning.
Emphasize Routine
Used to stress a habitual action done consistently at a certain time.
I check messages last thing before bed.
Not Literal
Sometimes it's not literal, just indicating early or late in a time frame or sequence.
Finish your homework first thing after your break.