http://revach.net/article.php?id=5227

Section: Parshas HaShavua   Category: Quick Vort
Parshas Vayikra: Oznayim LaTorah - Korban Olah V'Yored, Giving Up Your "Mun" for a Day

In Parshas Vayikra, among the many korbanos is the Korban Oleh V'Yored, whose offering depends on the wealth of the individual who did the aveira. The most modest option for a kapara is a Mincha which consists of one tenth of an eifah of flour.

The Oznayim LaTorah points out that this is the same amount as the Omer LaGulgoles which was the ration of Mun allotted for each person in the Midbar. The omer is the amount a healthy person needs to eat each day. The significance of this amount for the Olah V'Yored is that even a person who is destitute must give up eating one day and instead use his ration for a Korban.

Moreover says the Oznayim LaTorah, we find that Tzaddikim in the gemara would fast 40 days for a single small infraction. Certainly each person could stand to fast one day for his aveira.