What is the origin of the idiom "once and for all" and when to use it?

The idiom "once and for all" has roots in Middle English and can be traced back to the 14th century. It is an idiomatic expression that emerged from the combination of the individual words "once" and "for all," which have been used separately in English for much longer. This expression is used in personal situations to resolve conflicts or make firm commitments, in professional settings to establish clear guidelines or decisions, in legal matters to settle disputes conclusively, and in discussions or debates to assert a final position or settle an argument.