Question

Those who live in glass houses shouldn't throw stones essay

Answer 1

AJ
It means, those who criticise others often recognise those weaknesses because they have them themselves.

Imagine throwing a stone (or an insult) around inside a glass house (a greenhouse), your own house is destroyed. So rather than criticising others you should build strength to your own self by removing those weaknesses from your own life.

“I’m starting with the man in the mirror” would evoke the same idea.