This is a really interesting passage, particularly for a people spoiled by the customs of modern cleanliness. When we come upon grunge in our own houses, our cleaning kits are likely to contain gloves, bleach, hard brushes, etc., along with something to take care of the smell. When cleansing our bodies, we are likely to use soaps, shampoos, talcs, etc., as well as deodorants. But ritual cleansing takes an entirely different toolkit.
Leviticus 14 prescribes two birds, cedar wood, red yarn, and a hyssop sprig. Really. You can't make this up.
Here is the procedure: He must kill the one bird over a clay bowl containing fresh water. He must take the cedar wood, the hyssop sprig, the red yarn, and the living bird and dip them in the fresh water containing the blood of the bird that was killed. He must sprinkle the house seven times. So he must use the bird's blood, the fresh water, the living bird, the cedar wood, the hyssop, and the red yarn to make the house clean. Then he will let the living bird fly from the city into the open country. He will make peace with the Lord for the house, and it will be clean. (14:50-53)
Can you see the threads of the cross running through here?
There is a bird, and it is sacrificed so that its blood can be mixed with fresh water. And there is a Christ who is sacrificed, and from His very side, blood and water flowed. The bird's blood is poured into the clay bowl; the Christ's blood is spilled on the clay earth.
There is cedar wood; there is a wooden Cross. There is a hyssop sprig; the soldiers offered Jesus a drink from a hyssop sprig. There is red yarn; there are streams of red blood flowing from Christ's body and brow.
There is a sacrificial bird whose blood is spilled and a living bird who flies into the open country; there is a Christ who dies on the Cross and there is an empty tomb just outside the city.
The whole ritual for ritual cleansing is offered on the Cross. It's Levitical law, Golgotha-style. It's the priestly atonement, made by the priest Himself. It's the bird offering, once again, made by the Lamb of God.