Having the understanding darkened,.... Not that the natural faculty of the understanding is lost in men, nor the understanding in things natural and civil, and which is quick enough, especially in things that are evil; but in things spiritual it is very dark and ignorant, as about the nature and perfections of God, his holiness and righteousness; about sin and the consequences of it; about Christ, his person, office, and work, and salvation by him; about the Spirit, and his work of grace upon the soul; and about the Scripture, and the doctrines contained in it; and so it came to be by sin: the understanding of man was at first filled both with natural and divine knowledge; but man was not content with this, and being ambitious of more, even of being as God, lost what he had; for on account of his sin he was banished from the divine presence, which brought not only a darkness upon him, but upon all his posterity; and which is increased by personal iniquity, and oftentimes by Satan the god of this world, who blinds the minds of men; and sometimes men are given up in just judgment by God, to a judicial blindness and hardness of heart; and which issues in utter darkness, in blackness of darkness for evermore:being alienated from the life of God; not that which God lives in himself, but that which he lives in his people; nor that natural life which men receive from him, but a spiritual life, a life of grace, faith and holiness; and which may be called the life of God, because it is infused by the Spirit of God, and the word of God is the means of it, and it is supported and secured by the power of God, and is according to the will of God, and is directed to his glory: now wicked and unconverted men are alienated from this life; they are estranged from God the fountain of it; and go astray from the law, the rule of an holy life; and are entirely destitute of a principle of life, from whence men can only act and are utterly unacquainted with the pleasures and sweetness of the life of faith and holiness; nor do they approve of such a life, but have the utmost aversion to it:through the ignorance that is in them; every unregenerate man is an ignorant man, and especially the Gentiles were very ignorant of God, and of divine things; ignorance is natural to men, it comes by sin, and is itself sinful, and is sometimes the punishment of sin, and also the cause of it, as here of alienation from the life of God; for where is ignorance of God, there can be no desire after him, no communion with him, no faith in him, had dependence on him; no true worship of him, or living according to his will, and to his glory: and this ignorance is,because of the blindness of their hearts, or "the hardness of it"; there is a natural hardness of the heart, the heart is naturally stony, and so it remains till grace takes away the stony heart, and gives an heart of flesh; it is insensible and inflexible, and not susceptive of any impression; and there is a voluntary hardness of it, men willingly harden themselves against the Lord, and make their hearts like an adamant stone, all sin is of an hardening nature; and there is a judicial hardness, which God gives up men unto; and when and where this is the case, in either sense, it is no wonder men should be so ignorant of God, and so alienated from the life of him:blh twymo, "blindness of heart" , is a Rabbinical phrase.
T. Bab. Cetubot, fol. 105.