Spanish to English Other Idioms / Maxims / Sayings

This is a text from Argentina from the late 19th century, though the expression is still used. It means to talk about something that you don't really know about, another expression for the same thing in Spanish is "versar". I can't come up with the right term in English without falling into obscenity ("talking out your a...")
The context is:
Es fácil que alguno de mis lectores criollos, sobre todo algunos de los que están tocados de la “ironía canalla” de que XXX nos habla, imaginándose que estoy macaneando, me interrumpa por lo bajo, diciéndome...

Thanks