expression
stop talking nonsense; don't be ridiculous; give me a break
A set phrase used to sharply tell someone they are speaking foolishly. Often carries a tone of exasperation or contempt. The literal meaning is 'even a fool should rest before speaking', implying that the listener's words are so absurd they should take a break from talking.
そんな計画が成功するわけないだろ。馬鹿も休み休み言え。
There's no way that plan will succeed. Stop talking nonsense.
自分が一番だなんて、馬鹿も休み休み言えよ。
Saying you're the best? Give me a break.
A set phrase combining 馬鹿 (fool), も (even), 休み休み (taking breaks), and 言え (imperative of 言う, 'say'). The literal sense is 'even a fool should rest before speaking', used idiomatically to tell someone they are talking nonsense.