This insertion removes all difficulty very simply. Be is omitted constantly.
"Till supper-time alone; while then God be with you."
This line cannot be as the poet wrote it, for the metric accents fall on 'be' and 'you.' We might read good bye, but it would be somewhat too familiar. On the whole, I think that mean has been omitted before 'while.' By supplying it, the language becomes dignified and king-like. See Index s. v. [While].
"To make them kings, the seed of Banquo kings!
Rather than so come Fate into the lists."
"Now, if you have a station in the file,
Not in the most worst rank of manhood, say it."