All the days of his separation Some were perpetual Nazarites, being peculiarly devoted to God from the womb, as Samson and John the Baptist. But Moses here speaks of such as made themselves Nazarites only for a time, which might be longer or shorter, as they thought fit to appoint.
Related Commentaries of Numbers 6:4
Numbers 6:4
4 All the days of his separationb shall he eat nothing that is made of the vine tree, from the kernels even to the husk.