Elevating Weekday Time to the Holiness of Shabbos

We are obligated to add some weekday time onto Shabbos. We light candles 18 minutes before sunset, and we wait until after it is dark before making Havdallah after Shabbos. This is compared to a wolf, which pounces on its prey from in front and behind. It also represents the general work of elevating mundane worldly matters to holiness.

(See talk of the Lubavitcher Rebbe King Moshiach Shlita, Va’eira 2 5752 (1992))