An outgrowth of the passing child sacrifice was the custom of smearing blood on the house doorposts for the protection of the first-born. [1]
During his last year at school, when he was twelve years old, Jesus remonstrated with his father about the Jewish custom of touching the bit of parchment nailed upon the doorpost each time on going into, or coming out of, the house and then kissing the finger that touched the parchment. [2]