Six in the fourth place makes the only unqualified promise in The Family. It shows the household enriched and gives great good fortune, and a querent drawing it is being told that the accumulation currently underway is sound and needs no correction. Lines this favourable are rare enough in the classic that the honest thing is to say so plainly rather than to go hunting for a warning the text has not put there.
What the line does supply is a caution by omission. It is a yielding stroke and it enriches by being correctly positioned rather than by acquiring anything, so a reading landing here concerns a benefit arriving because an arrangement is working properly, not because of anybody's exertion. Treating the result as personally earned is the error the silence leaves room for, since nothing in the text credits initiative and the entire verdict rests on placement.
When the line changes, the upper trigram Xun becomes Qian and the figure becomes Fellowship, King Wen 13, people out in the open acting in concert beyond the ties of any single household. The destination says what a well provided family is for. Resources gathered inside a set of walls become, at this station, the capacity to associate with people outside them, and the classic treats that widening as the natural continuation of the fourth line rather than as a departure from it.