הפרשת חלה
There is a well known Mishna in מסכת שבת that said that women could die in childbirth for not observing Nidda laws, Shabbat candles, and not separating the dough when baking Challa. The Mitzva is called, הפרשת חלה.
The source for this ruling, is alluded to in פרשת בחוקותי. The תוכחה, Rebuke, has many curses that will happen to the Jewish people if they do not fulfill the commandments. In chapter 26:16, it is written, והפקדתי עליכם בהלה, “I will assign upon you panic.”
The Talmud explains that really the word, בהלה, meaning, “panic,” should really be בחלה, “with Challah,” hinting to the non-observance of this important Mitzva of הפרשת חלה.
This is an indication that we must never take any Mitzva lightly, as we do not fully understand the value of any particular commandment. It is Hashem, who ultimately decides and evaluates how we are judged, in the manner that we practice Judaism.
This is said clearly in Pirkei Avot where it says that we judge every light Mitzva as a strict one, as we do not know the true reward for Mitzvot.
The separation of חלה, is one very good example.