In the Amidah's benediction for Thanksgiving during Chanukah, we include ‘And thank You for the wonders and salvation of Your priests which You have wrought in the days of Mattathias, son of Joḥanan, High Priest, and the Hasmoneans his sons..." [This is] likewise mentioned in the Grace after meals.

The whole Hallel is recited during all the eight days of Ḥanukkah.

When Adam Harishon, saw that the day was progressively diminishing, as the days become shorter from the autumnal equinox until the winter solstice, he did not yet know that this is a normal phenomenon. Therefore he said: "Woe is me! Perhaps, because I sinned the world is becoming dark around me and will ultimately return to the primordial state of chaos and disorder." [He] arose and spent eight days in fasting and in prayer. Once he saw that the season of Tevet, i.e., the winter solstice, had arrived, and saw that the day was progressively lengthening after the solstice, he said: "Clearly, the days become shorter and then longer, and this is the order of the world." He went and observed a festival for eight days. Upon the next year, he observed both these eight days on which he had fasted on the previous year, and these eight days of his celebration, as days of festivities.

The days of Chanukah are known as “days of thanksgiving,” which implies a taste of the World to Come--for the essence of the delight of the World to Come is thanking and praising God’s great name.

It is knowing and acknowledging the Divine, through which we come nearer and closer to God.