give someone enough rope
give (one) enough rope
If you give people the opportunity to do something wrong or detrimental to themselves, they will usually do it; one does not need to interfere to bring about someone's downfall. The full version is, "Give (one) enough rope, and (one) will hang (one)self." Don't interrupt him with questions. Just let him keep talking and he'll incriminate himself. Give him enough rope and see what happens.
give someone enough rope (or plenty of rope)give a person enough freedom of action to bring about their own downfall.
The fuller form of this expression is the proverb give a man enough rope and he will hang himself , which has been in use in various forms since the mid 17th century.