Why Did Isaac Call Rebekah His Sister? (Genesis 26:1–11)

The rain failed in Canaan a second time, and in the hungry land the LORD appeared to Isaac and spoke. It is the first time Genesis records God's voice in Isaac's ears, and the first thing God promised him was Himself.

"Now there was another famine in the land, subsequent to the one that had occurred in Abraham's time. And Isaac went to Abimelech king of the Philistines at Gerar" (Genesis 26:1). Beyond Gerar lay Egypt and the Nile, where his father had gone the last time the rain failed (Genesis 12:10).

Why did God tell Isaac not to go down to Egypt?

God told Isaac to stay because the famine-struck land was the land He had sworn to give him, and He wanted Isaac to trust Him there. "The LORD appeared to Isaac and said, 'Do not go down to Egypt. Settle in the land where I tell you'" (Genesis 26:2).

Egypt had a river. Canaan had rain, and the rain had stopped. Isaac heard the voice of God and stayed where every harvest depended on Him: "So Isaac settled in Gerar" (Genesis 26:6).

What did God promise Isaac in Genesis 26?

God promised Isaac His presence first, and then everything He had sworn to Abraham. "Stay in this land as a foreigner, and I will be with you and bless you. For I will give all these lands to you and your offspring, and I will confirm the oath that I swore to your father Abraham" (Genesis 26:3).

Isaac had grown up on the story of that oath. Now God spoke it to him by name, and gave the reason it had come down to him: "because Abraham listened to My voice" (Genesis 26:5). To know God is to know a Father who keeps what He said to the last generation and says it again to the next.

Then the men of Gerar started asking about Rebekah.

Why did Isaac say Rebekah was his sister?

Isaac lied because he was afraid the men of Gerar would kill him to take his beautiful wife, and in that moment he believed his fear over God's promise to be with him. "But when the men of that place asked about his wife, he said, 'She is my sister.' For he was afraid to say, 'She is my wife'" (Genesis 26:7).

His father had told the same lie in Egypt (Genesis 12:13) and again in Gerar (Genesis 20:2). The son who obeyed God about Egypt lost hold, a few verses later, of the promise that came with the command, and reasoned as a man alone among strangers.

God kept him anyway. Abimelech saw Isaac caressing Rebekah from a window, called him in, and then gave an order to protect them: "Whoever harms this man or his wife will surely be put to death" (Genesis 26:11). "The fear of man is a snare, but whoever trusts in the LORD is set securely on high" (Proverbs 29:25).

How does Jesus fulfil God's promise to be with Isaac?

Jesus fulfils it by being God with us in person. Matthew names Him at His birth: "they will call Him Immanuel" (which means, "God with us") (Matthew 1:23). The last sentence of Matthew's Gospel is Jesus giving that promise to His church: "And surely I am with you always, even to the end of the age" (Matthew 28:20).

Paul says the promises to Abraham's seed meant "One, who is Christ" (Galatians 3:16). Isaac carried that promise for one lifetime; in Christ every believer hears it from the mouth of God.

Read the promise again when you are afraid

When God speaks to you, write it down in the Doxa app with the date and the words as you heard them. On your own afraid day, open it and read it again before you decide what to say. We are the people who remember what God has said, and He stays with His own for the whole journey.

What has God said to you that you are tempted to forget when you are afraid?

Deeper study today in the Doxa Deeper Dive: the two Hebrew words God used to promise Isaac His presence, and why Moses heard them again at the burning bush. Read it here.