Isaac, like his father Abraham, perceived danger in that if he was to say that Rebekah was his wife; they may kill him in order to have her.
Rebekah was actually related to Isaac; she was the daughter of Bethuel. Bethuel was Isaac’s first cousin, the son of Nahor. Nahor was the brother of Abraham. Of course, Abraham was the father of Isaac. So, Rebekah was the granddaughter of Milcah and Nahor, making her a second cousin to Isaac.
After some time of residing in Gerar, Abimelech king of the Philistines, saw Isaac fondly playing with Rebekah which suggested they were not just brother and sister. Abimelech called Isaac in and wanted to know why he lied to him about Rebekah. Isaac was truthful and told him he was afraid he would be killed for her. Abimelech chided him for what he done because of the guilt that would have been upon them if someone would have taken Rebekah as their wife.
Abimelech proclaimed to his people that no one touch Isaac or Rebekah; else they be put to death. This sounds very familiar when thinking upon Abraham.
Isaac farmed the land and the LORD greatly blessed him in his yield, a hundred fold. Isaac continue to prosper and also became wealthy with flocks, herds, and servants. The Philistines came to envy him.
The wells that Abraham dug were plugged by the Philistines by filling them with dirt and Abimelech sent Isaac away because of his magnitude of flocks and servants. Isaac and company moved to the valley of Gerar.
Rebekah has an important role to play in bible history. After consideration, Rebekah was willing to return with the servant to marry Isaac and her family was willing to let her go. And through that, God gave Isaac a gift of love—a wife whom he would love to soothe his heart wounded by his mother’s death. Rebekah was given a husband who would love and care for her. But we know that there was more at stake here. In God’s kindness, He often layers in levels of meaning in what He does. We see that here. Yes, God wanted to provide a wife for Isaac for his good, but He was also providing a wife for Isaac for His own glory. God was still at work extending the family through which Jesus would come. This is why Rebekah matters. God used Rebekah just as much as Isaac in Jesus’ family tree. Rebekah was a faithful, humble, loving woman who brought Isaac comfort in that day, and indirectly, several years later, played a role in bringing all humanity comfort through Jesus Christ.