John Gill Commentary Numbers 6:8

"All the days of his separation he is holy unto Jehovah." — Numbers 6:8 (ASV)

All the days of his separation he [is] holy unto the Lord .
Set apart for his service, separate from all others, especially the dead, and under obligation to abstain from the above things; from drinking wine, from shaving his hair, and from defiling himself for the dead, and to be employed in holy and religious exercises during the time his vow is upon him.