the outdoor sermon...
little butterflies 1822
60 years old, On March the third son born, On August injured by
slipping on the road, wrote the books of haiku.
no dangi wo tsui to torimaku ko chô kana
A Buddhist priest gives a sermon in a field--probably about Amida's saving grace. Several "pious" butterflies attend along with the people.
Tsui to can mean satto ("suddenly") or migaru ni ("with agility"); Kogo dai jiten (Shogakukan 1983) 1075.
This is not sermon but just only conversation on the field.
Dangi means speaking formal topic, but is not used only for religious content.
I think Issa saw villagers talking on the field. They discussed mean less topic that happened in the village.
He would wish to tease them.
Now you're cooking!