The priest is to offer one as a sin offering and the other as a burnt offering to make atonement for him because he sinned by being in the presence of the dead body. That same day he is to consecrate his head.
""Then the priest is to sacrifice the sin offering and make atonement for the one to be cleansed from his uncleanness. After that, the priest shall slaughter the burnt offering" -
"The priest shall then offer the other as a burnt offering in the prescribed way and make atonement for him for the sin he has committed, and he will be forgiven." -
"Include one male goat as a sin offering to make atonement for you." -
"Sacrifice a bull each day as a sin offering to make atonement. Purify the altar by making atonement for it, and anoint it to consecrate it." -
"one as a sin offering and the other as a burnt offering, together with the grain offering. In this way the priest will make atonement before the LORD on behalf of the one to be cleansed."" -