Florus, 10 (Di Giovine = Anthologia Latina 252)

consules fiunt quotannis et novi proconsules.
solus aut rex aut poeta non quotannis nascitur.

New consuls and proconsuls are created every year. Only a king or a poet is not born every year.

‘rex’ is ambiguous: following the political context of the first line it suggests the meaning ‘king’, but with ‘poeta’ in the second line it gains the added sense of a poet’s patron.