50) We see how Jesus understood John, namely that he wanted to know
whether hindering the man was right and in the interest of Jesus or not. Jesus
tells him that it is not right and adds the proof. As a rule (R. 851–2), the
command to stop an action already begun is expressed by the present imperative
with μή whereas the command not to begin an action has the ingressive aorist
subjunctive with μή. It does so here: μή κωλύετε = “stop preventing him.” And
the reason (γάρ) is that “he who is not against you is for you,” ὑπέρ, in your
favor. As far as the pronoun “you” is concerned, for which Mark 9:40 has “we,”
this refers to them as disciples of Jesus and thus involves Jesus just as much
as “we” does.
We should, of course, consider this terse dictum in its connection and
not in a mere abstract way. It applies to men like the one under discussion. It
does not apply to men who are merely indifferent to Jesus and are thus not
actively against him. Such indifference and coldness as a response to Jesus and
his revelation (name) would be “against” him and his disciples in a decided
way. To be lukewarm and neither hot nor cold is fatal. Thus, not to be against
the disciples of Jesus means, indeed, to be for them, at least to some degree.
Whoever appreciates Jesus and his name (revelation) enough to drop all
opposition to him and to his disciples is, to say the least, on a fair road to
becoming his enthusiastic follower.
This shows agreement with the dictum that is voiced in Matt. 12:30:
“He that is not with me (μετά) is against me (κατά).” Both dicta state the same
thing, but do so in opposite ways. One states who are for Jesus, the other who
are against him. Both imply that neutrality in regard to him is impossible. Whoever
comes in contact with Jesus and develops no hostility toward him and his is
already to a degree won for him and will soon confess this; but whoever
comes in contact with Jesus and forms no attachment for him is already to a
degree against him and will soon reveal this. The two dicta thus belong
together, each makes the other clearer. (R. C. H. Lenski, The Interpretation of St. Luke’s Gospel [Minneapolis:
Augsburg Publishing House, 1961], 550-51, emphasis in bold added)
