(Deuteronomy 12:6) says: "And you shall bring there your burnt-offerings and your sacrifices and the first-born of your herds and flocks." This seems to require bringing the first-born animal to the Temple. But the Mekhilta challenges this reading.
(Exodus 13:2) says: "In man and beast, he is mine." The first-born of a beast is likened to the first-born of a human being. And the first-born of a human being is likened to the first-born of a beast. What does this mutual comparison teach?
A human first-born need not be brought to the Temple for redemption. The father pays five shekels to any Kohen, anywhere. Since the Torah equates animal and human first-borns, the animal first-born similarly need not be brought to the Temple. The owner can give it to any Kohen, wherever he is.
This ruling overrides the implication of (Deuteronomy 12:6). While that verse seems to require bringing first-born animals to the Temple along with other offerings, the Exodus verse creates a different framework. By comparing the animal first-born to the human first-born — which is clearly not brought to the Temple — the Torah establishes that the first-born animal can be given to a priest anywhere.
Two verses point in different directions. The Mekhilta resolves the tension by giving priority to the comparison between human and animal first-borns, which overrides the implication of the Temple-centered verse.