The concept of עולם שנה נפש was revealed in Sefer Yetzirah. עולם means world or space; שנה – year or time; נפש – soul or object.
The rule is that whatever appears in one of them appears correspondingly in the others.
An example that many Seforim write about is, the Beis Hamikdash is in עולם – the world (it occupies space), correspondingly שבת is the Beis Hamikdash in שנה – time.
The Tiferes Shlomo and Sfas Emes write that although the world became further from Hashem after the Churban Beis Hamikdash, on Shabbos there is no impact of the Churban, since Shabbos is itself a בחינה of the Beis Hamikdash.
The Arvei Nachal says that the בחינה of Beis Hamikdash in the נפש is the heart. The Beis Hamikdash is the center of the world and the heart is the center of the human body. Hashem reveals Himself in the heart of every Yid, like He revealed himself in the Beis Hamikdash.
The Meor Einayim writes that Rosh Hashanah is the mind of the year, Yom Kippur the heart, and Succos the Da’as of the year.
This Yesod appears many times in Chassidus. With this Yesod, it is no wonder that the Torah commands Shabbos in this week’s Parshah and that the Melochos of Shabbos are learned from the Mishkan.