Ordinary bread [''bread from the earth''], which is the product of hard physical labor, is a metaphor for the ''revealed'' interpretations of the Torah [nigleh], found in the Talmud, which require arduous analysis, questioning etc. On the other hand, manna [''bread from heaven''] represents the mystical teachings of the Torah [chassidut], which are of such a ''heavenly'' nature that there is no disagreement, argument etc.
Logically speaking, a person might think that is is necessary to have a firm grounding in classic texts, and achieve a certain degree of spiritual greatness before one can progress to the study of Mysticism. However, the Torah teaches here that even the wicked individuals who complained to Moshe ate manna [Beha'alotecha 11:6]
From this we can learn that it is appropriate for people from all walks to life to study the mystical teachings of the Torah -particularly as they are formulated clearly and methodically in the teachings of Chabad.
Source: Based on Likutei Sichos vol 4 Lubavitcher Rebbe