To attain something in this world you have to subject other people to you, but to attain something in the Kingdom of God you must subject yourself, become the least. We find the third lesson connected to the child in this verse, which tells of the small and the unimportant which are great with God. In ancient times children were generally considered unimportant, someone who did not count. Both mills consisted of a round stone disc with a hole in the middle, which was then turned over another stone. It is obvious that Jesus is here speaking of the upperstone of the big mill, the donkey mill.
Temptations are unavoidable because of the lordship of satan and the influence of sin in the world.
But every man through whom temptation comes, is personally responsible. The first woe is a complaint of sadness at the state of the world, at those who are tempted. The second is a threatening indictment of those through whom temptation comes. Hand and foot speak of a man's actions and behaviour, of his deeds. In contrast, the eye is a member that does not give, but receives.