no use arguing; not up for discussion
Yojijukugo meaning that discussion or argument is pointless; often used to shut down debate or indicate that a decision is final.
At this point, there's no use arguing.
He made his demands without room for discussion.
Yojijukugo composed of 問答 (question and answer, discussion) and 無用 (useless, unnecessary). The exact historical derivation is uncertain, but the phrase is conventionally understood as 'argument is useless'.