John Calvin Commentary Genesis 3:4

"And the serpent said unto the woman, Ye shall not surely die:" — Genesis 3:4 (ASV)

And the serpent said unto the woman Satan now springs more boldly forward; and because he sees a breach open before him, he breaks through in a direct assault, for he is never accustomed to engage in open war until we voluntarily expose ourselves to him, naked and unarmed.

He cautiously approaches us at first with flatteries; but when he has stolen in upon us, he dares to exalt himself insolently and with proud confidence against God; just as he now, seizing upon Eve’s doubt, penetrates further, that he may turn it into a direct negative. We ought to be instructed by many examples to beware of his snares and, by making timely resistance, to keep him far from us, so that he is not permitted nearer access.

He now, therefore, does not ask doubtingly, as before, whether or not the command of God, which he opposes, is true, but openly accuses God of falsehood, for he asserts that the word by which death was threatened is false and deceptive. Fatal temptation! When God is threatening us with death, we not only sleep securely, but hold God himself in derision!