Why Isaac Went Blind Before the Blessing

The Torah does not explain why Isaac went blind. It simply notes the fact: "And it came to pass, when Isaac was old, that his eyes were dim" (Genesis 27:1). Then the narrative moves on to the blessings, to Rebekah's plan, to Jacob dressed in his brother's garments. Blindness is treated as background detail. The rabbis treated it as the whole point.

Aggadat Bereshit 40, preserved in a compilation from the ninth or tenth century CE, begins its treatment of this passage not with Isaac's blindness at all but with the question of old age itself, which the Torah introduces for the first time in Abraham's story. "Now Abraham was old, advanced in years" (Genesis 24:1). Before Abraham, the midrash observes, the Torah never mentions anyone aging. Twenty generations from Adam to Abraham passed without the text noting that any of them grew old. Abraham asked God to make aging visible, to give the body some indication that the end was approaching, so that people would have time to set their affairs in order. God agreed. Old age began with Abraham.

Isaac inherited this. He inherited everything from his father, the midrash says, in five categories: name, good deeds, wealth, strength, and wisdom. The physical parallel between Isaac and his son Joseph is drawn out carefully. Isaac was handsome and strong, just as Joseph would be. He dug wells throughout Canaan, the labor of his own hands. He became vastly wealthy in Gerar. He had received wisdom from God. And he lived to one hundred and eighty years (Genesis 35:28). The patriarch earned his old age. It was not just decline. It was completion.

But then the midrash stops and asks the hard question: why did God dim Isaac's eyes specifically before the blessing scene? This was not a side effect of aging. This was a plan.

God, the midrash says plainly, knew that Isaac loved Esau and intended to bless him. God also knew what Esau was. Esau had married two Hittite women who made the lives of his parents bitter (Genesis 26:34-35). He had sold his birthright for a bowl of lentils. The midrash is not sentimental about Esau: "A foolish son is a vexation to his father and bitterness to her that bore him" (Proverbs 17:25). God's response was precise. If Isaac could see, he would see Esau and bless him. Jacob would lose the blessing. The entire covenantal lineage would flow in the wrong direction. So God made it impossible for Isaac to see who was in front of him.

This is a theology that makes people uncomfortable: God intervening in human perception to ensure a particular outcome. The midrash does not apologize for it. It quotes Psalms directly: "You have done many wonders and thoughts for us" (Psalm 40:6). Israel's question back to God is honest: "Why do You do all these wonders? Why do You think these thoughts for us?" The implied answer is that God's interventions are not always comfortable or even comprehensible in the moment. Isaac genuinely believed he was blessing Esau. He was not deceived by God about his own intentions. He was given the gift of not being able to act on those intentions.

Isaac and Rebekah both called Esau "the elder." They meant it as a title of honor. The midrash records God's response to this: "Who else in My world rules without Me? Why do you call him the elder in My house? I have made him small" (Obadiah 1:2). The measuring rod is God's, not the parents'. A mother's assessment and a father's love are not the final word on a person's stature.

Old age brought Abraham his most important achievement, the arrival of Isaac. Old age brought Isaac his most important crisis, the blessing of the wrong son. Old age brought the intervention of God, bending the story back toward its intended arc. The rabbis who preserved this in Midrash Aggadah understood that blindness and blessing were not opposites in this story. They were the same thing.

What looks like a father's failure of sight is actually a father being shielded from his own mistake. The dim eyes are mercy, not punishment. Isaac could not see who was in front of him. What he could not see, he could not ruin.