The third line is the most violent in the hexagram and the classic reports it without commentary. Legge's translation shows a carriage being dragged back while the oxen drawing it are pushed the other way, and the man himself subjected to the shaving of the head and the cutting off of the nose, and then says there is no good beginning but there will be a good end. Those two mutilations were penal practices of the period the text comes from, sentences carried out on the body and legible to anybody who saw the person afterwards, and they are given here as the text has them rather than turned into a figure of speech.
The weight of the line lies past the punishment, in the sequence. Everything about the beginning is obstruction: the vehicle held from in front, the animals held from behind, and the driver marked in a way that cannot be undone. The classic softens none of it and explains none of it, and then it says the end will be good. What the line describes is a course stopped at every point of its outset that completes regardless.
The stroke is yielding in an odd place and incorrectly seated at the top of the lower trigram Dui, hemmed between the strong second line below and the strong fourth above, which is the structural reason it is caught from both directions at once. Its proper correlate is the topmost line of the hexagram, and that is where the good end comes from. Nothing in the third line's own position produces the reversal. It arrives from the one place in the figure that is looking straight at it.