Their mother saw the opportunity for a moral lesson.

母亲认为这是进行品德教育的好时机。

youdao

This story contains a profound lesson.; The moral of the story is profound.

这个故事寓有深意。

《新英汉大辞典》

A second lesson is that remedies for moral hazard will always be imperfect.

第二个教训是，对道德风险的补救措施永远是不完美的。

youdao

Depositors' losses served as a lesson in moral hazard.

ECONOMIST: Hong Kong's economy

It provides us with a lesson, a moral, a path to our own future.

FORBES: Book Review: Douglas Brunt's "The Ghosts of Manhattan"