As with many slang and idiomatic phrases, the origin can be a bit unclear. The first recorded use of the phrase cut the mustard was by O. Henry in 1907, in a story called The Heart of the West: “I looked around and found a proposition that exactly cut the mustard”. The modern sense of the idiom is ‘to succeed; to have the ability to do something; to come up to expectations’, but the phrase is most often used in the negative form, as “can’t cut the mustard,” meaning ‘not able to handle the job’. The cut probably refers to harvesting the plant, so if one cannot cut the mustard, one cannot supply what is best. A phrase preceding cut the mustard is to be the mustard (c. 1903) meaning ‘to be special’ or ‘to be exactly what is needed’ withmustard being a slang term for importance. There is also another phrase keen as mustard meaning ‘very enthusiastic’.