犬いぬが西にし向むきゃ尾おは東ひがし

expression

that goes without saying; water is wet

A humorous, idiomatic way to state the obvious. Literally 'when a dog faces west, its tail points east'.

• 「犬いぬが西にし向むきゃ尾おは東ひがし」って、当あたり前まえのことを言いうときに使つかうんだよ。

  You use 'inu ga nishi mukya o wa higashi' when stating the obvious.

• そんなの犬いぬが西にし向むきゃ尾おは東ひがしだよ。わざわざ言いうことじゃない。

  That's like saying water is wet. You don't need to point it out.