Tirar o cavalo da chuva

Literally: To take the horse out of the rain

Example: “Se esperas um aumento este ano, podes tirar o cavalo da chuva.” — If you're expecting a raise this year, don't hold your breath.

English equivalent: Not to hold one's breath

Origin: The usual explanation comes from rural Brazil, when visitors came on horseback: a visitor tied his horse outside, and only if the host invited him to stay longer did he move it out of the rain into shelter. Hoping to take one's horse out of the rain was hoping for a long welcome, and being told to forget it became giving up on an expectation. The story is widely repeated, often dated to the 19th century, but no source documents it. The phrase is also tirar o cavalinho da chuva.