The fourth line offers one of the hexagram's most concrete images: a sack tied up, in Legge's rendering, drawing neither blame nor praise. Where the first three lines described frost, straightforward virtue, and hidden excellence, the fourth line describes deliberate closure, a container sealed so that nothing inside it can be seen or judged from outside. The verdict is neither favorable nor unfavorable; it is simply neutral, and that neutrality is presented as the entire point.
The line sits at the lowest place of the upper trigram Kun, the second Earth stacked above the first, and this position, opening a new trigram, is traditionally read as a place of caution rather than action, a first test of whether the receptive quality built through the lower trigram can hold steady at a higher and more exposed register. The sack tied up answers that test by withdrawing altogether: rather than risk speaking or acting at a moment when either could bring trouble, the line counsels sealing oneself off from judgment entirely.
Commentary tradition often reads this line as advice for a time when the surrounding circumstances are genuinely dangerous for open speech, a court or household where honesty could easily be punished rather than rewarded. The line does not treat this silence as cowardice; it treats it as the correct reading of the moment, and the absence of both blame and praise is offered as success rather than failure, since avoiding harm is itself the achievement the line describes.