In last week’s Parsha, we have a reference to the Mitzva of the redemption of a first born donkey by a lamb. This is called פדיון פטר חמור. It is a ceremony that is still done today.
There is a Bracha recited, and the holiness that the first born donkey had, is transferred to the lamb. Even though donkeys are non-Kosher animals, they are rewarded because they helped carry the riches of Egypt on their backs during the exodus.
The Parsha noted that when the Leviim were chosen to replace the first born in the Temple, the בהמת הלויים, the animal of the Leviim, replaced בהמתם, their animals (plural).
Quoting the beginning of מסכת בכורות, it was learned that one lamb of the לוי, was able to redeem numerous פטר חמור’s of the other tribes. It was because of the text where the לוי’s animal was written in singular, and the animals of the other tribes, was written in plural.