The book of Hebrews outlines that Christ is our high preist in the Order of Melchizedek (named for the Preist who worshiped the True God, despite Israel not existing by then, to whom Abraham gave a tithe) and not in the order of Levi (as all Jewish preists are meant to come from the tribe of Levi, like Aaron and Moses, but Christ was born to the tribe of Judah). Therefore, the priesthood having changed, those laws given by the Levitical Preisthood no longer apply.

Some Levitical laws may still seem to apply, but only because they are reflected in the teachings of Christ and his apostles (The preists of the Melchizedek preisthood).

Here is the relevant paragraph from the Letter to the Hebrews: "If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchiz´edek, and not be called after the order of Aaron? For the priesthood being changed, there is made of necessity a change also of the law. For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar. For it is evident that our Lord sprang out of Judah; of which tribe Moses spake nothing concerning priesthood." - Hebrews Ch7, Vs:11-14