What exactly does the phrase people in glass houses shouldn throw stones mean?
It’s more metaphorical. If you live in a glass house – you shouldn’t throw stones – as this would provoke others to retaliate and throw stones back at you – which would destroy your ‘glass house’. So in line with this, it basically means – if you can easily be critisized on a topic, don’t be hypocritical and preach to others, when your situation is just as sensitive.
