Mishna: At Mincha of the last day [of Pesach], they would make a declaration [lit., an admission]. What was the declaration? "I removed the sacred from the house" – this is ma’aser sheni and neta revay – "I have given it to the levi" – this is the ma’aser given to the levi – "and I have also given it" – this is teruma and terumat ma’aser – "to the foreigner, the orphan, and the widow" – this is ma’aser ani, leket, sikcha, and pei’ah, even though [not doing so] is not an impediment – "from the house" – this is challa.

Ein Ayah: It is true that the greatness of a person’s obligation in the service of Hashem has to be engrained in him. He must have holy actions and paths. He must straighten his thoughts and attributes very clearly until he realizes the great unlikelihood that even his greatest efforts to pursue goodness and righteousness will enable him to fulfill his obligations fully. Therefore, the righteous view themselves as incomplete and possess a special type of humility.
However, this trait of lack of satisfaction in one’s righteousness should not have too much impact on a person to the extent that it steals his tranquility and happiness and thereby diminishes his intellect, Torah knowledge, and every good attribute. Therefore, the Torah provided a reminder that a person must feel satisfaction and even verbalize that he has done good things. This realization strengthens the emotion he puts into his service of Hashem, making it proper to have satisfaction and joy when he has fulfilled his obligations and not always view himself as lacking. Just as the soul benefits greatly when one admits his sins, so is there value in declaring his mitzvot.
Admittedly, one’s self-critical declarations should exceed those of self-credit, to avoid a tendency toward laziness. That is why the Torah set a declaration that accompanies the mitzvot of separating and giving certain obligatory contributions. These mitzvot encompass all six categories of obligations of the Torah and the intellect: negative mitzvot, positive mitzvot, mitzvot of the community, mitzvot of the individual, mitzvot between man and Hashem, and mitzvot between man and his fellow man.
Being careful not to eat tevel is an example of a negative commandment. The separation of tithes, the calling of the name of each, and the giving of each to its proper recipient are positive mitzvot. The specific mitzva to give the gifts is a mitzva of the individual, whereas the general idea of sustaining the kohanim so that they can lead the service of Hashem and teach Torah is a mitzva of the community. Considering the recipients’ rights to their portions is a mitzva between man and his fellow man. The concept of teruma’s sanctity and the need to remove the prohibition from the tevel are examples of mitzvot between man and Hashem.
Thus, properly adhering to the many obligations of special donations encompasses the gamut of man’s obligations to man. Therefore, the mitzva to make a declaration upon completing these mitzvot correctly reminds us of the general principle that we should not exaggerate our harsh outlook on our own spiritual achievements. Rather we should view ourselves honestly with open eyes and knowledge of how to be happy in our heart when we have done good deeds. Then we can look for our shortcomings and act strongly to fix them, with the help of the impetus created by the contrast between our happiness from achievement and disappointment from moral failure.
Therefore, we need declarations of mitzva fulfillment along with declarations of sin and healthy measures of straightness and modesty. One’s feeling of modesty should make him reluctant to announce his achievements. That is why he makes the declaration at the last possible moment, at the end of the last day of the holiday. This demonstrates that he is declaring his goodness only to fulfill the obligation with which Hashem presented him.