Suddenly Isaac leaned forward so far that his backside rose up from the ground and he had to support himself on the knuckles of his hands; he looked for all the world like a hyena or baboon challenging an intruder. “A man gives himself to God,” said Isaac, “because he belongs only to himself. If my sons are given to God, it will be because Rebekah and I taught them well enough that they chose to give their lives in his service.”

“So there’s no reason for me to be alive at all,” said Abraham. “I have nothing to offer, nothing that anyone wants. How tedious the burden must be, to have me still alive.”

Isaac slumped and rocked back onto his seat on the rugs. “If you don’t already know that I love you, there’s nothing I can do now to prove it.”

“Love me? When did you ever show you loved me?”

This was too outrageous for Rebekah to bear. “Every day of his life he shows you! He follows all your teachings, he serves God as you did, he shows nothing but respect for you!”

But Isaac brushed away her defense with a gesture of his hand. “I’ll tell you when I showed you I loved you, Father. When I lay there under the knife, knowing I had the strength to take it away from you and walk away free—but I loved you more than I loved my own life.”

“That was God’s command, not mine,” said Abraham.

“You were obeying God, but I was obeying you.”

Abraham’s breath became rapid and shallow. “After all these years, you rebuke me as if it were my idea. I thought you understood.”

“I did understand,” said Isaac. “To you, it was God taking your son. But to me, it was my father giving me up.”

Now, finally, Rebekah understood. The story she had heard from Ezbaal’s grandmother, who had learned it from Ishmael—it was true. There had been a time when Abraham stood ready with a knife to sacrifice Isaac. To sacrifice him to God, even though Abraham’s whole life had been a struggle against the sacrificing of human beings to slake the imagined bloodthirst of nonexistent gods.

“I hated it,” said Abraham. “It was the most terrible command the Lord ever gave me.”

“And yet . . . you said yes.”

“So did you,” said Abraham.

Isaac looked down. “I’m not sure,” said Isaac.

“I was an old man. You were young and strong. You let me bind you.”

“I’m not sure whether I said yes to God, or to you.”

“God was testing our faith,” said Abraham.

“How do you know he wasn’t testing our love?”

“By that standard,” said Abraham, “your love for me was perfect, and mine for you . . . failed.”