Here’s another flatulence-related saying! Enjoy!
(He to kaji wa moto kara sawagu;
“Farts and fires make noise from the source”)
The one who caused a problem often complains about it the most. “The one who smelt it, dealt it.” The person who passed gas is often the first and loudest to complain about a smell, and the person or household that caused a fire (for example, by letting their cooking-fire get out of control) is often the one that makes the most fuss about there being a fire.
We begin with our main noun from last week, 屁 (he, like “heh”), a fart. It is joined by the conjunctive particle と (to, like “toe”) to compound noun 火事 (kaji), “conflagration” – literally, “fire thing.” These are collectively signaled to be the topic of discussion by the topic marker は (wa).
Next we get the noun 元 (moto), “origin,” “source,” “foundation.” The particle から (kara) marks it as the start or origin point of something. And finally, that something is given as the verb 騒ぐ (sawagu), in sentence-final form. Sawagu has a range of related meanings, but relevant to this context are “to make noise” and “to panic,” “to make a fuss.”
Not a lot to add on this. There are a couple of variations on this saying with the same meaning. There are a surprising number of further fart-related sayings and idiomatic expressions as well, but any more than two would probably be pushing my luck. I leave the rest as an exercise to the reader.
「え～、臭っ！誰かおならした？」 「太郎や、屁と火事は元から騒ぐって言うんじゃない？ 」 「ああ．．．」
(“Eee, kusa’! Dareka onara shita?” “Tarou ya, he to kaji wa moto kara sawagu tte iun ja nai?” “Aa….”)
[“Egh, that reeks! Did someone fart?” “Tarou, don’t they say that ‘The one who smelt it dealt it‘?” “Ah….”]