The karanga culture is very strong on justice and ensuring that one is rewarded for the good deeds or suffer the repercussions for bad deeds. As such the justice system was such that no wrong would go unpunished regardless of when it occurred. So strong was (and still is in some cases) this notion that there was no statute of limitation as is the case in most modern or western laws. In fact crimes or wrongs could be rectified by children or grandchildren of the wrongdoer or the punishment or censure could be meted down on the children. Hence this proverb was essential in tying up the entire family and/or the descendants of the wrongdoer as a deterrent to wrong doers.
The proverb is used as a deterrent to wrongdoers to remind them that their wrongs will eventually be brought book. It can also be used as a reminder to those who have finally been brought to book that there is no way they should have expected to get away with it.