That covenant made between me and his progenitors for themselves and their posterity, whereby I promised to give them an everlasting priesthood, Numbers 25:12,13, and they covenanted with me that they would faithfully and holily execute that sacred function according to the rules which I gave them, whereby, among other things, they were enjoined to keep themselves pure from all unlawful marriages, and from all other things which might pollute them or the priesthood.
Related Commentaries of Nehemiah 13:29
Nehemiah 13:29
29 Remember them, O my God, because they have defiled the priesthood, and the covenant of the priesthood, and of the Levites.