He shall then wash his clothes and bathe his body in water and be clean. (Leviticus 14:9)
Before a cleansed leper could return to a state of levitical purity, he needed to go through a ritual immersion in water. The Hebrew word for a gathering of water suitable for ritual immersion is mikvah (מקוה).
Immersion into a mikvah is a standard ritual for most purification ceremonies in the Torah, not just for lepers. In the Greek, immersion into the mikvah was expressed with the Greek term baptisma, from which we derive the word baptism. In the Torah, baptism is the prescribed mode of purification for a variety of ritual contaminations.
"Baptism" is an interesting word because it means different things to different people. In the Apostolic Scriptures, baptism is one of the fundamental rites practiced by Yeshua and His followers. Throughout church history, the mode and meaning of baptism have been points of bitter contention and hatred between sects of Christendom. Even today, baptism is a divisive word. To some it is a covenant ritual administered to infants through sprinkling at birth, something analogous to circumcision. To the other side of the Christian world, it is an immersion into water carried out by an immerser. The pastor or elder of the congregation actually dunks the adult parishioner under the water as a testimony of faith.
The church cannot be blamed for her confusion over administering the rite of baptism. The problem is that the Apostolic Scriptures afford scanty details regarding the ritual. They say very little about the mode, never explaining exactly how a person is to be baptized. They say a bit more about the symbolism, but even this seems to be largely taken for granted. There are many stories about people being baptized, but the stories don't spell out the details of how the baptism was accomplished. It seems as if the apostolic writers thought that the method and procedure of baptism was so well known that they were under no compulsion to record any of the details of the ritual. The writer of the book of Hebrews even refers to baptism as one of the elementary principals of faith in Messiah. It was one of the basic concepts of faith. To the apostles and the early believers, baptism was so basic that there was no need to describe it in detail.
The reason the method and procedure of baptism was obvious to the apostolic writers is that the apostolic writers were all Jews, and baptism was a common Jewish ritual. The ritual of immersion began with the purity laws of Torah. Before entering into the Tabernacle and the presence of God, every Israelite needed to be purified.
So baptism was not a Christian invention or even an apostolic innovation. From the days of Moses, baptism was regularly practiced by all of Israel.
