Reb Tzaddok: Shabbat II

Reb Tzadok HaKohen of Lublin (Yisrael Kedoshim #8) writes that when we
thank Hashem in the Minchah of Shabbos for providing us with the potential
to achieve a Menuchas Emes Ve’emuna­ a rest of truth and belief — we are
referring to our potential to attain the level of that very pious
individual.  For the ideal Menuchas Shabbos in which even in the depth of
our hearts we regard all weekday matters as having been completed and no
longer requiring our attention.

It does not suffice for us to do the minimum, to refrain from forbidden
activities yet at the same time allow our hearts to continue being
distracted by our commerce and craft. Only such a state can rightly be
termed a Menuchas Emes, for truth is that which penetrates to our greatest
depths and remains consistent. A “truth” that only “holds true” on a
superficial level (refraining from expressing concern over weekday matters,
yet at the same time considering, these matters in our mind) cannot be
called “true.” Such superficial truth might fool other people, but not
Hashem, concerning whom it is said Chosamo Emes ­ his seal is truth.

Thus, while refraining from mundane conversation is a technical fulfillment
of the command to desist from expressing oneself in weekday matters, it is
not a Menuchah Sheleimah (a truly complete, befiting rest).

Hence, concludes Reb Tzadok, those who are in awe of G-d because they are
cognizant of Hashem’s knowledge of that which is concealed deep in one’s
heart are extremely meticulous and vigilant in barring any weekday thoughts
from their minds.