A Bird and a Leper
To read the Bible in a year, read Leviticus 14.
The day would hopefully come in the life of a leper when he could be pronounced clean. Thus, Leviticus 14 dealt with that potential day. One of the interesting things about the cleansing of the leper was this, "And the priest shall command that one of the birds be killed in an earthen vessel over running water" ( Leviticus 14:5). God then explained what was to be done with the blood (v. 1-9).
A person might be pronounced clean of leprosy, but a bird died in the process. The lessor died for the greater. That was the case in the Old Testament. However, in the New Testament the Greater died for the lessor. The Greater did not die for our fleshly cleansing, but He died that we might live in the Spirit.