Here is Ambrose, interpreting the story of Namaan, the Syrian. What is so great about it is the last paragraph where he takes the figure of the young maid who points Namaan to the prophet as a picture of the church. Wonderful! The church points to THE prophet, Christ, who washes us clean in the eternal Jordan of Holy Baptism.
Lastly, let the lessons lately gone through from the Kings teach you. Naaman was a Syrian, and suffered from leprosy, nor could he be cleansed by any. Then a maiden from among the captives said that there was a prophet in Israel, who could cleanse him from the defilement of the leprosy. And it is said that, having taken silver and gold, he went to the king of Israel. And he, when he heard the cause of his coming, rent his clothes, saying, that occasion was rather being sought against him, since things were asked of him which pertained not to the power of kings. Elisha, however, sent word to the king, that he should send the Syrian to him, that he might know there was a God in Israel. And when he had come, he bade him dip himself seven times in the river Jordan.
Then he began to reason with himself that he had better waters in his own country, in which he had often bathed and never been cleansed of his leprosy; and so remembering this, he did not obey the command of the prophet, yet on the advice and persuasion of his servants he yielded and dipped himself. And being forthwith cleansed, he understood that it is not of the waters but of grace that a man is cleansed.
Understand now who is that young maid among the captives. She is the congregation gathered out of the Gentiles, that is, the Church of God held down of old by the captivity of sin, when as yet it possessed not the liberty of grace, by whose counsel that foolish people of the Gentiles heard the word of prophecy as to which it had before been in doubt. Afterwards, however, when they believed that it ought to be obeyed, they were washed from every defilement of sin. And he indeed doubted before he was healed; you are already healed, and therefore ought not to doubt.
On the Mysteries, Chapter 3, 16-18.