Galatians 4:23

What is the meaning of "after the flesh?" Having said that Faith united us to Abraham, and it having seemed incredible to his hearers, that those who were not begotten by Abraham should be called his sons, he proves that this paradox had actually happened long ago; for that Isaac, born not according to the order of nature, nor the law of marriage, nor the power of the flesh, was yet truly his own son. He was the issue of bodies that were dead, and of a womb that was dead; his conception was not by the flesh, nor his birth by the seed, but the Word of God fashioned Him. Not so in the case of the bondman; He came by virtue of the laws of nature, and after the manner of marriage. Nevertheless, he that was not according to the flesh was more honorable than he that was born after the flesh. Therefore let it not disturb you that ye are not born after the flesh; for from the very reason that ye are not so born, are ye most of all Abraham's kindred. The being born after the flesh renders one not more honorable, but less so, for a birth not after the flesh is more marvellous and more spiritual. And this is plain from the case of those who were born of old time; Ishmael, for instance, who was born according to the flesh, was not only a bondman, but was cast out of his father's house; but Isaac, who was born according to the promise, being a true son and free, was lord of all.