The fourth line of Obstruction (King Wen 39) is drawn as yin, the numeral six in the old divination manuals. James Legge's translation renders the line as going forward leads to difficulty, remaining still he joins with those in a correct place. The image sits inside a hexagram whose judgment as a whole concerns advantage found in the southwest, and the contrary in the northeast, advantage in seeing the great man, and in being firm and correct, 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 upper trigram Kan, water in Legge's readings of the eight trigrams, while the lower trigram of the hexagram is Gen, mountain in the same traditional set of images. The Great Symbolism of the hexagram reads water above a mountain; the superior man turns round to examine himself and cultivates his virtue, and the fourth line takes its place inside that combined picture of Gen below and Kan above.
Read on its own the line neither opens nor closes the hexagram's argument. It marks the point where Kan is either forming (in the lower trigram) or completing itself (in the upper), and later interpreters treat its image, Joining Those in a Correct Place, as the concrete case through which the hexagram's abstract judgment becomes visible in a single situation rather than a general principle.