In order to explain the difference between these two modes of Avodah in a person’s service of Hashem, the Alter Rebbe explains in ‘Likkutei Torah’ that this is the difference between Torah and Mitzvos. Torah is in a state of ‘Mishkon’. In other words, the G-dliness within is in a state of revelation.
As our sages have extrapolated from the verse: הֲלוֹא כֹה דְׁבָרִי כָאֵש “Is My Word not like fire?” Meaning that the words of Torah are not susceptible to ‘Tumah’ [or] in other words they cannot become impure, (just as fire cannot). This does not only apply to the Torah itself but also to all the words of Torah which are studied by any Jewish person [-they too] are not susceptible to ‘Tumah’.
Whereas, [by contrast] Mitzvos are specifically connected with physical objects that need to be refined. Due to this the Torah is primarily studied using one’s Chochmah and Seichel in one’s head, whereas Mitzvos are primarily done in deed.
This is the ‘אֹֹֽהָלֶיךָ יַעֲקֹב’ and the ‘מִשְׁכְׁנֹתֶיךָ יִשְׁרָאֵל’. [In summation’] because the Avodah in performing Mitzvos (Connected with Ohel) is through ‘Yaakov’ the letters ‘עֵקֶב - י’ which is the state of ‘Maaseh’ - of action, [this contrast with] the Avodah of Torah study (connected with Mishkon) [which] is through ‘Yisroel’ containing the letters ‘רֹאש ’.
