What is the origin of the idiom at wits end?

What is the full block format of an invitation letter? Why is there a necktie on someone's doorknob? In a wedding program would the word Mothers have an apostrophe in the item Rose Presentation to the Mothers of the Bride and Groom? How i write a Leave application as we was out for yesterday for a important work? Who reprimanded Penelope for not greeting Odysseus appropriately? Who should you introduce first and ordinary person or the person in authority? What does it mean when someone bends over in front of you? What is the meaning of the idiom go off accidentally? What is the meaning of curtsy? What does it mean when a woman puts her hands behind her head and exposes her arm pits in a meeting? What does it mean conduct your self properly? What does Ami de tous anu de personne mean? How is mother-in-law called in Punjabi? What does the quote ''kings and bears often worry their keepers'' mean? What is the protocol for who to invite to a military graduation function is a Supervisor allowed to bring his girlfriend? What is the present perfect tense of invite in Jeff invite Pete and Maria to his house for dinner? What are steps to prevent or resolve misunderstanding between visitors and staff? How do you say to wear or not to wear in french? What is a personal phrase? What is the meaning of 'What you give always comes back'?