ויהי אנשים אשר היו טמאים לנפש אדם ...למה נגרע לבלתי הקריב את אדם קרבן ד' במועדו
Some men were ritually impure due to contact with a human corpse, and they could not sacrifice the Pesach-offering on that day … These men said, “We are ritually impure through contact with a human corpse. Why should we be diminished, so as not to bring the offering of Hashem on its appointed time?” (9:6) One must be ritually pure in order to offer the Korban Pesach (or any Korban for that matter). These men were tamei meis, ritually impure, due to their contact with a human corpse. Confronted with the circumstance, they came to Moshe Rabbeinu and offered their…
