What is the meaning of [Give knave an inch and they will take a yard]

If you grant some people a small favour, it only encourages them to take much
more than they are offered.

> ‘I told old Joe to help himself to some strawberries, and when I went out
into the garden later in the morning, I found he’d pinched the lot.’

> ‘Never trust old Jose. Give him an inch and he’ll take a yard.’