The first arcanum names the error of a word given and not kept: a promise, an oath, a vow, an arrangement that someone in the lineage relied on — and was left with nothing. This is not about a forgotten trifle, but about a word for the sake of which a person changed their life.
In a descendant it comes back as the storyline of "we agreed and it fell through". Arrangements collapse at the last moment, partners disappear, what others promised never arrives. Often a person catches themselves promising easily and keeping their word with difficulty — and does not notice that they are repeating the very thing they suffer from.
What counts as working it off is absolute exactness in one's word. Not to promise what you are not sure of; to do what you said in the small things, where nobody would notice; to close old obligations even if the deadline passed long ago and nobody is waiting any more. Not a heroic gesture, but a habit built up over years.