Shavua Tov. After the death of the two sons of Aharon, Moshe Rabbeinu gets angry at Aharon's surviving sons, Elazar and Itamar. He was really upset with Aharon but expressed it to his two nephews.
On that day, the first of Nissan, three sacrifices were offered. One was by the Nassi, or tribal head, Nachshon of Shevet Yehuda. A second sacrifice was for the inauguration of the Mishkan, and a third was the regular sin-offering of Rosh Chodesh.
The Kohanim were to eat a portion of all three sacrifices. Aharon declined eating from the third sacrifice. For this, Moshe was upset and asked why they didn't eat of the חטאת, the sin offering.
Aharon explained that the first two sacrifices were once in a lifetime sacrifices so he agreed to eat from them. But the third sacrifice was a regular monthly sacrifice and he was in a state of אונן, where he was busy with burying his dead. Aharon felt that it would not be pleasing in the eyes of Hashem to partake of such a sacrifice.
Moshe showed his greatness and humility by accepting his brother's argument. In essence, he was admitting he was wrong. This was most praiseworthy and set a great example for all of us to follow. There's no shame in admitting when we are wrong. It takes a big person to do this.
Yesterday was eleven with ספירת העומר