John Chrysostom
By the very sight, persuading them to humility and simplicity; for this little one was pure from envy and vain glory, and from a desire of superiority. But He does not only say, If ye become such, ye shall receive a great reward, but also, if ye will honour others, who are such for my sake. Wherefore there follows: And when he had taken him in his arms, he said unto them, Whosoever shall receive one of such children in my name, receiveth me.
Matthew however says, that the disciples came to Jesus, saying, Who is the greatest in the kingdom of heaven? (Matt. 18:1) The reason is, that he did not begin the narrative from its commencement, but omitted our Saviour’s knowledge of the thoughts and words of His disciples; unless we understand Him to mean, that even what they thought and said, when away from Christ, was said unto Him, since it was as well known to Him as if it had been said to Him. It goes on: For by the way they had disputed among themselves, who should be the greatest. (Luke 9:46. Vulg.) But Luke says, that “the thought entered into the disciples which of them should be the greatest;” for the Lord laid open their thought and intention from their private discourse1 according to the Gospel narrative.
The disciples indeed wished to receive honour at the hands of the Lord; they also had a desire to be made great by Christ, for the greater a man is, the more worthy of honour he becomes, for which reason He did not throw an obstacle in the way of that desire, but brought in humility.