substitute one thing for another; suffer in another's stead
Meanings
2 senses · 4 examplesidiom
to substitute one thing for another; to replace the original with a substitute
literaryOften used in strategic or planning contexts where a less valuable or more expendable person/thing is substituted to protect or advance a more important one.
To preserve the main force, they decided to field the second team; this was merely a strategy of substituting one for another.
During an economic crisis, the government sometimes has to adopt a strategy of substitution, sacrificing short-term interests to achieve long-term stability.
idiom
to suffer in another's stead; to bear the blame for someone else
literaryThis usage emphasizes the aspect of taking on blame, punishment, or hardship that rightfully belongs to another person.
The real person responsible fled, yet he was forced to bear the blame in their stead and took on all the guilt.
In this story, the elder brother chose to suffer in his younger brother's stead to protect him.