Origen

(tom. xx. 2. et sq.) Or we may explain the difficulty thus. Above it is in the Greek, I know that ye are Abraham’s seed. So let us examine whether there is not a difference between a bodily seed and a child. It is evident that a seed contains in itself all the proportions of him whose seed it is, as yet however dormant, and waiting to be developed; when the seed first has changed and moulded the material it meets with in the woman, derived nourishment from thence and gone through a process in the womb, it becomes a child, the likeness of its begetter. So then a child is formed from the seed: but the seed is not necessarily a child. Now with reference to those who are from their works judged to be the seed of Abraham, may we not conceive that they are so from certain seminal proportions implanted in their souls? All men are not the seed of Abraham, for all have not these proportions implanted in their souls. But he who is the seed of Abraham, has yet to become his child by likeness. And it is possible for him by negligence and indolence even to cease to be the seed. But those to whom these words were addressed, were not yet cut off from hope: and therefore Jesus acknowledged that they were as yet the seed of Abraham, and had still the power of becoming children of Abraham. So He says, If ye are the children of Abraham, do the works of Abraham. If as the seed of Abraham, they had attained to their proper sign and growth, they would have taken in our Lord’s words. But not having grown to be children, they cared not; but wish to kill the Word, and as it were break it in pieces, since it was too great for them to take in. If any of you then be the seed of Abraham, and as yet do not take in the word of God, let him not seek to kill the word; but rather change himself into being a son of Abraham, and then he will be able to take in the Son of God. Some select one of the works of Abraham, viz. that in Genesis, And Abraham believed God, and it was counted to him for righteousness. (Gen. 15:6) But even granting to them that faith is a work, if this were so, why was it not, Do the work of Abraham: using the singular number, instead of the plural? The expression as it stands is, I think, equivalent to saying, Do all the works of Abraham: i. e. in the spiritual sense, interpreting Abraham’s history allegorically. For it is not incumbent on one, who would be a son of Abraham, to many his maidservants, or after his wife’s death, to marry another in his old age.