I asked my informant if she knew any proverbs and “kill ’em with kindness” came up as she is a mother of two and tells this to her kids when they encounter bullies or rudeness.

Me: What do you mean when you say “kill ’em with kindness” and when do you use it?

CC: When my kids are bullied or encounter mean or rude people and are angry and either want to retaliate or give up, I tell them to kill ’em with kindness. The mean people of the world, just be nice to them, and they can’t bother you, you don’t stoop to their level. It’s always the best way to deal with mean people.

Me: Where did you learn this?

CC: From my own mother I suppose? I grew up Catholic, and this isn’t strictly a Catholic saying, but it goes along with the values of kindness and turning the other cheek. It’s a good way to live by, being kind and not reciprocating rudeness.

Analysis:

This is a proverb coming from a suburban Catholic family, specifically from  a mother. It means as she says to not reciprocate rudeness, but to treat the rude people with kindness instead and the situation will get better and not elevate like it would if rudeness was reciprocated with rudeness. It also goes along with teaching kids not to react and retaliate, but to be kind. It may be a modern, colloquial iteration of some Proverbs from the Bible.

Annotation: This proverb has some similar iterations in Proverbs of King James Bible.

Prov 25:21, 22: If your enemy is hungry, give him food; if 
he is thirsty, give him water.  When you do this, he will feel 
ashamed of hating you and the Lord will reward your compassion.