Commentary for Job 14:4

Who can bring a clean thing from a putrid drop, and semen, which is unclean? Not one of them is clean, that he should not sin.

If, despite all the arguments to the contrary, God does in fact govern and there is individual Providence, then it should take account of two factors: (i) man's inherent uncleanliness by reason of the manner of his conception and birth; (ii) that man has no free-will, his fate being predetermined from above.⁶During the 18th century a fierce debate raged between those who believed that the growth and development of an embryo was 'epigenetic', i.e., all its limbs and parts emerge from the primordial material and become recognizable at the same rate, and those who believed in the doctrine of 'preformation' according to which the primordial germ already contains a miniature replica of the adult and this only has to enlarge and unfold before birth. Whereas the former theory required an agency which conjured the limbs from the undifferentiated primordial material the latter just involved an inherent mechanical process. Aristotle, who advocated the epigenetic model, regarded the semen as being the spiritual agency that conjured the limbs and other body parts from the menstrual blood.
True to his eclectic ways, Malbim combines elements of both theories in his interpretation of this verse as a demand that God make allowances for man's innate unclean tendencies when he judges him. As he writes:
For is the branch not always like its root and the plant like the seed from which it grew? And so, how can man who is born out of uncleanliness, for he is born of woman – from semen and menstrual blood which is an unclean thing – how can he change his nature and not be at one with the lowliness of the source of his birth 'and the quarry from which he was hewn' (Isaiah 51.1)? He therefore tends to uncleanliness from his birth and from the womb and from conception.