Deuteronomy 21:5
And the priests the sons of Levi shall come near; for them the Lord thy God hath chosen to minister unto him, and to bless in the name of the Lord; and by their word shall every controversy and every stroke be tried: (Deuteronomy 21:5)
Priests.
 See chs. 17:9; 18:1. The priests of the nearest Levitical city would be present to see that the requirements were carried out in harmony with what had been commanded, for “by their word,” literally, “upon their mouth,” all such cases were to be settled. The authority of the Levites was far reaching. They had a voice in every important decision. In this case their presence gave validity to the placing of the burden of the murder on the district in which the body was found.