perfectly justified 天经地义

“天经地义”，汉语成语，出自《左传·昭公二十五年》：“夫礼，天之经也，地之义也，民之行也（Rites represent the rules governing the movement of heaven and earth as well as the code of conduct for the people. ）。”

天经地义本意是指“天地的规则与秩序（the rules and orderliness of heaven and earth）”，后来被广泛地用以描述各种事物的正当性及不容置疑的道理（the expression later came to mean anything that is proper, or any reasoning that is justified）。可以翻译为“right and proper；perfectly justified”。

例句：

杀人偿命，天经地义。

It is only right and proper that murder is punished by death.