What does the へさうな mean in "逢へさうな"


I've come across this phrase (逢へさうな) and don't really understand what's going
on grammatically. It's in the context of haiku poetry, I'm assuming the kanji
reading is just "a" as in "逢う", but I can't find this form elsewhere online to
know if it's an idiom or a particular conjugation of the verb. Any insight
would be appreciated.




This is not [particle-へ](/questions/tagged/particle-%e3%81%b8 "show questions
tagged 'particle-へ'").

Rather it is old _kana_ orthography and さう sound-shifted to そう. In modern
orthography it is

> 逢えそうな【あえそうな】

(Many monolingual dictionaries list old _kana_ orthography of the entries
where applicable, but of course the particular inflection あへさう would not be
listed under あう.)

