'Themselves' in the Bible

In those times, a number will take up arms against the king of the south: and the children of the violent among your people will be lifting themselves up to make the vision come true; but it will be their downfall.

And some of those who are wise will have wisdom in testing themselves and making themselves clean, till the time of the end: for it is still for the fixed time.

Till a number are tested and make themselves clean; and the evil-doers will do evil; for not one of the evil-doers will have knowledge; but all will be made clear to those who are wise.