Christ, and the graces of Christ, are called Manna. Manna means to prepare, because it was food prepared from heaven for the Israelites in the wilderness.
Mediator as applied to Christ, is borrowed from persons, whose office it is to reconcile such parties as are at variance, being as it were in the middle, betwixt both, soliciting the cause of each to the other, till they bring them to concord or agreement.
By Milk here, we must understand the doctrine of the Gospel, which is easily taught unto the capacities of such as are children in understanding.
Amongst the many metaphors that our blessed Saviour is expressed by in the holy scriptures, certainly this of the Door must carry emphasis and signification, for use and improvement; otherwise He that was wiser than Solomon, and spake as never man spake, (for excellency of matter and form) would never have likened himself to a Door.
You may have heard of the Four-H Club for young people run by the U. S. Department of Agriculture. But I want to bring your attention to the Four-H Principle of Christian Service.