Literal translation
to do master Arnaud's accounts
Meaning
to make muddled, misleading calculations
Explanation
This phrase means 'to make muddled, misleading calculations' or, more broadly, 'to tell a story that is tangled and somewhat manipulated'. The expression plays on the sound and sense closeness between the verb for telling a tale and the verb for counting, the two actions of narrating and calculating brought together here to suggest that a story can hide a self-interested calculation, and that a calculation can be nothing more than a cleverly arranged tale. 'Master Arnaud' remains a figure whose exact identity escapes our sources: the title 'master' suggests a local notable, perhaps an accountant, a moneylender, or a businessman whose reputation for dishonesty with figures was once enough to turn his name into a proverbial example, though the precise anecdote behind it can no longer be traced today. The expression is used to call out a calculation or an account deliberately made confusing, meant to mislead the listener, in a familiar register tinged with amused suspicion.