Purity Through Love of a Fellow Jew
The whole purpose of the Parah Adumah, said Rav Yitzchok, is the mitzvah of loving your fellow Jew.
On the verse that the kohen is impure until evening, Rav Yitzchok taught that the heart of the Parah Adumah, the entire process of cleansing the spiritually impure, is the mitzvah of loving your neighbor. His grandson Rav Mendel of Vorka later explained the connection. The kohen who helps with the purification becomes impure through the very act that makes someone else pure. He gives up something of his own so that another can be cleansed. That, said the Rebbe, is the most complete love for another Jew. And when a person truly loves someone, he does not feel the cost as a loss. He finds real pleasure in every sacrifice he makes on that person's behalf.
Source: On Bamidbar 19:7. Attributed to Rav Yitzchok in published English accounts of his Torah, which say his teachings were collected in Ohel Yitzchak; the page in Ohel Yitzchak is not pinned.
Choose one person this week and do something for them that costs you a little: an hour you would have kept for yourself, a favor you would normally skip, or a ride you did not have to offer. Do it quietly, without mentioning it. Afterward, notice whether you feel poorer or lighter. The Rebbe taught that real love finds joy in the cost. Even a small sacrifice can begin teaching your heart that lesson.