"Βασιλεὺς Ἀντίγονος Ζήνωνι φιλοσόφῳ χαίρειν."

[Vicoland]

Why does it use χαίρειν? Is it to show purpose, or just a habit?
I am a beginner, waiting for someone kind to offer an answer.

[jeidsath]

The imperative “χαῖρε”, “rejoice!” gets used like English “hello!”

It is often an infinitive at the beginning of letters, as if the author were writing “so-and-so λέγει χαίρειν = says hello[rejoice!]”

[Vicoland]

The imperative “χαῖρε”, “rejoice!” gets used like English “hello!”

It is often an infinitive at the beginning of letters, as if the author were writing “so-and-so λέγει χαίρειν = says hello[rejoice!]”

Thanks!