Likutei Halakhot, Orach Chaim, Laws of Morning Hand Washing 2:10/ליקוטי הלכות·אורח חיים·הלכות נטילת ידים שחרית ב׳:י׳

11. This corresponds to the filling of the moon, as in, "the light of the moon will be like the light of the sun, like the light of the seven days of creation" (Isaiah 30:26), which will take place in the future, when divine providence will be revealed in the world. The darkness of night will then be eliminated and the moon will be filled of it’s waning, for the waning of the moon corresponds to the darkness of night, to natural sciences, which are attached to it since their main power is from the waning of the moon as is known. In the future though, the moon will be filled and darkness will be eliminated, for nature itself will be eliminated and Providence will be revealed. And then 'the night will be as bright as the day', corresponding to, 'the light of the moon will be as the light of the sun'. Therefore, the commandment to sanctify each new month is the first commandment given to the Jews in Egypt during the redemption, for the essence of redemption is the elimination of nature, corresponding to the filling of the moon, which corresponds to the sanctification of the month.