Son of David, Son of Rahab

"Since, if we were recounting the race of a mere man, one might naturally have been silent touching these things [sinful people in a genealogy]; but if of God Incarnate, so far from being silent, one ought to make a glory of them, showing forth His tender care, and His power. Yea, it was for this cause He came, not to escape our disgraces, but to bear them away. Therefore as He is the more admired, in that He not only died, but was even crucified (though the thing be opprobrious, yet the more opprobrious the more doth it show Him full of love to man), so likewise may we speak touching His birth; it is not only because He took flesh upon Him, and became man, that we justly stand amazed at Him, but because He vouchsafed to have also such kinsfolk, being in no respect ashamed of our evils. And this He was proclaiming from the very beginnings of His birth, that He is ashamed of none of those things that belong to us; while He teaches us also hereby, never to hide our face at our forefathers' wickedness, but to seek after one thing alone, even virtue....For this end he hath mentioned Ruth also and Rahab, the one an alien, the other an harlot, that thou mayest learn that He came to do away with all our ills. For He hath come as a Physician, not as a Judge." (John Chrysostom, Homilies on Matthew, 3:3, 3:5)