A.T. Robertson Commentary Matthew 18

Who then is greatest (τις αρα μειζων εστιν). The αρα seems to point back to the taxcollection incident when Jesus had claimed exemption for them all as "sons" of the Father. But it was not a new dispute, for jealousy had been growing in their hearts. The wonderful words of Jesus to Peter on Mount Hermon (Matthew 16:17–19) had evidently made Peter feel a fresh sense of leadership on the basis of which he had dared even to rebuke Jesus for speaking of his death (16:22). And then Peter was one of the three (James and John also) taken with the Master up on the Mount of Transfiguration. Peter on that occasion had spoken up promptly. And just now the tax-had singled out Peter as the one who seemed to represent the group. Mark represents Jesus as asking them about their dispute on the way into the house, perhaps just after their question in Mt 18:1. Jesus had noticed the wrangling. It will break out again and again (Matthew 20:20–28; Luke 22:24). Plainly the primacy of Peter was not yet admitted by the others. The use of the comparative μειζων (so ο μειζων in verse 4) rather than the superlative μεγιστος is quite in accord with the Koine idiom where the comparative is displacing the superlative (Robertson, Grammar, pp. 667ff.). But it is a sad discovery to find the disciples chiefly concerned about their own places (offices) in the political kingdom which they were expecting.

Called to him (προσκαλεσαμενος). Indirect middle voice aorist participle. It may even be Peter's "little child" (παιδιον) as it was probably in Peter's house .

Set him (εστησεν). Transitive first aorist active indicative, not intransitive second aorist, εστη.

In the midst of them (εν μεσω αυτων). Luke adds (Luke 9:47) "by his side" (παρ' εαυτω). Both are true.

Except ye turn and become (εαν μη στραφητε κα γενησθε). Third-class condition, undetermined but with prospect of determination. Στραφητε is second aorist passive subjunctive and γενησθε second aorist middle subjunctive. They were headed in the wrong direction with their selfish ambition. "His tone at this time is markedly severe, as much as when He denounces the Pharisaism in the bud He had to deal with" (Bruce). The strong double negative ου μη εισελθητε means that they will otherwise not get into the kingdom of heaven at all, let alone have big places in it.

This little child (το παιδιον τουτο). This saying about humbling oneself Jesus repeated a number of times as for instance in Mt 23:12. Probably Jesus pointed to the child by his side. The ninth-century story that the child was Ignatius is worthless. It is not that the child humbled himself, but that the child is humble from the nature of the case in relation to older persons. That is true, however "bumptious" the child himself may be. Bruce observes that to humble oneself is "the most difficult thing in the world for saint as for sinner."

In my name (επ τω ονοματ μου). For "one such little child" (ανψ βελιεςερ ιν Χριστ) Luke (Luke 9:48) has "this little child" as a representative or symbol. "On the basis or ground of my name," "for my sake." Very much like εις ονομα in 10:41 which does not differ greatly from εν ονοματ (Acts 10:48).