Six in the fourth place is read as permission to rely on somebody above, and the contrast the hexagram itself sets up is worth drawing out. The second line made the same upward approach and was told it brought misfortune. This line is told the opposite, and the whole difference lies in whether the source approached is actually able and obliged to answer. A querent landing here is being told that the support they are looking to is real, that asking for it is not a failure of independence, and that persistence in the asking is appropriate.
The tiger's steady downward gaze, with desire pressing on and on, is the conduct the line prescribes. It rules out two failures at once: the wandering attention that the opening line's slack jaw depicts, and the diffuse solicitation of the second line, which reached in every direction and secured nothing. What is asked for instead is a single fixed object of attention and an unembarrassed persistence toward it. The line sits at the base of the upper trigram Gen, mountain, so that persistence is steady rather than agitated.
When the line changes, the upper trigram Gen becomes Li and the figure becomes Biting Through, King Wen 21, which concerns removing an obstruction by decisive means. The movement suggests where a well directed reliance leads. Not to permanent dependence, but to the point at which whatever stands between the querent and what they need is dealt with directly.