Mark 10:43

But so shall it not be among you
Or "so let it not be", as in many copies; or as the Persic version renders it, "it ought not to be so among you"; such a lordly spirit does not become you; this is heathenish:

but whosoever will be great among you shall be,
as in Matthew "let him", ( Matthew 20:26 ) , be

your minister.
This was just the reverse of what the two disciples were seeking for; they were indeed for being ministers but then they were for being prime ministers of state; and would have had all the rest subject to them and attendants on them to be sent out and employed as they should think fit: whereas the only way to preferment and greatness in Christ's kingdom, or rather Gospel church state, is to labour, in the work, of the ministry more abundantly than others; to take great pains and endure great hardships in order to bring great glory to God, and do great good to the souls of men; (See Gill on Matthew 20:26).