The first line of Limitation (King Wen 60) is drawn as yang, the numeral nine in the old divination manuals. James Legge's translation renders the line as not going beyond the courtyard's outer gate, no error. The image sits inside a hexagram whose judgment as a whole concerns progress and attainment, but if the regulations it sets are severe and difficult, they cannot be maintained for long, and this line supplies one stage of that larger reading rather than a complete statement on its own.
Structurally the line stands at the lowest place of the lower trigram Dui, lake in Legge's readings of the eight trigrams, while the upper trigram of the hexagram is Kan, water in the same traditional set of images. The Great Symbolism of the hexagram reads water above a marsh; the superior man constructs his methods of numbering and measurement, and considers points of virtue and conduct, and the first line takes its place inside that combined picture of Dui below and Kan above.
Read on its own the line neither opens nor closes the hexagram's argument. It marks the point where Dui is either forming (in the lower trigram) or completing itself (in the upper), and later interpreters treat its image, Not Going Beyond the Courtyard's Outer Gate, as the concrete case through which the hexagram's abstract judgment becomes visible in a single situation rather than a general principle.