The first section of the book is a short one entitled "Exordium." It tells the story of a man who deeply admires the story of Abraham in Genesis 22, admiring it more and more as he grows older, but understanding it less and less. More than anything, this man wants to witness the event, to watch Abraham, in order to understand how Abraham did what he did. The man ponders over four possible scenarios, each accompanied by an analogy to a mother weaning her child.
In the first, Abraham explains to Isaac that he is to be sacrificed, but then pretends to be a homicidal psychopath, so that his son will blame Abraham, and not God, for his death, and not lose faith in God. The man draws the analogy of a mother blackening her breast in order to wean the child: the breast changes, but the mother remains the same.
In the second, Abraham did what God told him to do, but did it reluctantly and uncomprehendingly. Forever after, Abraham was changed, and unable to feel joy. The man draws the analogy of a mother concealing her breast so that the child feels it no longer has a mother to draw milk from.
In the third, Abraham assumes God is testing him in a different way, to see how dearly he loves his son. Abraham rides alone to Mount Moriah and begs God's forgiveness for having even considered sacrificing Isaac. The man points out that both mother and child mourn over the weaning, as the child will never be closer to the mother than to her breast.
In the fourth, everything goes as planned, but Isaac sees at the last moment that Abraham clenches the knife in despair. Forever after, Isaac's faith is lost. The man remarks that when a mother must wean her child, she has more solid food at hand to feed the child.
Johannes tells us that the man ponders these and many other scenarios, never managing fully to understand Abraham.