Literal translation
when Jesus wore short trousers
Meaning
a very long time ago
Explanation
This expression points to an extremely distant past, so old that it blends into the childhood of the world itself. The literal image summons the child Jesus wearing a braieto, the short garment worn by little boys before adulthood: to invoke that time is to place an event so far back that it precedes living memory. The phrase works through playful exaggeration, in a familiar, often mildly ironic register, used when one wants to stress that a thing dates from a bygone era or that a habit reaches back to time immemorial. It is typically used in reply to a question about how old some usage, object, or custom is, much as one might say in ordinary French du temps de Mathusalem. The word braieto, meaning underpants or shorts, gives the phrase its concrete, popular flavour, rooted in everyday life. The expression remains very much alive in spoken Provençal, passed on through family banter.