"Seest thou by how many things He is urging to the care of our mean brethren. Say not then, "Such a one is a blacksmith, a shoemaker, he is a ploughman, he is a fool," and so despise him. For in order that thou shouldest not feel this, see by how many motives He persuades thee to practise moderation, and presses thee into a care for these. He set a little child, and saith, "Be ye as little children." And, "Whosoever receiveth such a little child receiveth me;" and, "Whosoever shall offend," shall suffer the utmost penalties. And He was not even satisfied with the comparison of the "millstone," but added also His "woe," and commanded us to cut off such, though they be in the place of hands and eyes to us. And by the angels again that are entrusted with these same mean brethren, He makes them objects of veneration, and from His own will and passion (for when He said, "The Son of Man is come to save that which was lost," He signifies even the cross, like as Paul saith, speaking of a brother, "For whom Christ died"); and from the Father, for that neither to Him doth it seem good that one should perish; and from common custom, because the shepherd leaves them that are safe, and seeks what is lost; and when he hath found what was gone astray, he is greatly delighted at the finding and the saving of this."
St John Chrysostom, on Matthew 18