information:classification, linguistic:paraphrasing
Early rabbinic sources

...After this, the sons of Israel went up to the Temple and rebuilt its gates and purified the Temple from the dead bodies and from the defilement. And they sought after pure olive oil to light the lamps therewith, but could not find any, except one bowl that was sealed with the signet ring of the High Priest from the days of Samuel the prophet and they knew that it was pure. There was in it to light for one day, but the God of heaven whose name dwells there put therein his blessing and they were able to light from it eight days. Therefore, the sons of Ḥashmonai made this covenant and took upon themselves a solemn vow, they and the sons of Israel, all of them, to publish amongst the sons of Israel, that they might observe these eight days of joy and honour, as the days of the feasts written in the Law; to light in them so as to make known to those who come after them that their God wrought for them salvation from heaven. In them, it is not permitted to mourn, neither to decree a fast, and anyone who has a vow to perform, let him perform it.