Not much is said about Issac in the Bible. He was not like Abraham, "the father of faith," nor like Jacob who wrestled with God. To Abraham the promises were given and in Jacob we see the epic struggle between the natural man and his spirit. Issac's life seems rather dull in comparision to that of his father's and his son's. On the surface, he seems to serve little more than a link. But there was really quite a bit more to Isaac.
After Abraham's death, there was a famine. Issac went to Abimelech, king of the Philistines in Gerar. The Lord appeared to him there and told him not to go down into Egypt but to sojourn in Gerar. The Lord repeated the promises He had given Abraham to Issac. Issac dwelt in the city of Gerar and the Lord blessed him until he grew so great that it alarmed the people there. Abimilech told him to leave. So Issac left and pitched his tent in the valley of Gerar. Issac was forced to leave his comfort zone and strike out.
Issac was back in the wilderness - the place of testing, the place where one is plowed. There was no water because his father's wells had been stopped up. After Abraham's death the Philistines had stopped up all the wells that Abraham had dug. So, Issac began re-digging them. And he called their names after the names by which his father had called them. The very fact that the wells had names is significant. There was meaning and purpose that had been discovered by Abraham while digging these wells and it had to be rediscovered by the son. There were also new wells to be dug and meaning and purpose for Issac to discover on his own.
Issac's servants dug a well in the valley and the herdsmen of Gerar fought with Issac's herdsmen, saying it was theirs. Issac called the well "Esek" because they "strove with him." Issac dug another well but was forced to strive for and lose that one too. He called it "Sitnah."
So Issac moved and dug yet another well and this time no one tried to take it. He named that well "Rehoboth" which meant: "Now the Lord has made room for us and we will be fruitful in the land." And Issac went from there to Beer-sheba. The same night the Lord appeared to him. And he said, "I am the God of Abraham, your father. Do not be afraid, for I am with you. I will bless you and multiply your offspring because of my servant Abraham."
Then Issac built an altar and worshipped the Lord right there. And he dug another well.
The next day Abimilech traveled from the city of Gerar to Issac. When he arrived, Issac was surprised and asked him why he had come since Abimilech "hated him and had driven him away." Abimilech confessed that the Lord had blessed Issac and he wanted a peace covenant with Issac. Abimilech said, "You are now blessed of the Lord. I think there should be an oath between us."
Something had happened to Issac from the time he left Gerar until that present moment. He had a testimony. Abimilech recognized it. Driven from his home and everything that was comfortable and settled, Issac had to move out and trust God. And God had come through for him.
Why had Abraham's wells been stopped up after his death by the Philistines? It is always the conflict of the natural man's strength against the faith of the spiritual man. Stop up the source of the spiritual man's life and he will be powerless. There will be no advancement of the kingdom. There will be no occupation. There will be no room for him in the land. It has always been this way and will continue until the Lord's return I suppose. How rare are true men and women of faith. How true the scripture that says the world is not worthy of them.
Where was Issac when his father's wells had been stopped up? I assume he was preoccupied with life in the city. But when he was forced to move out, to take up the journey again, to walk by faith, to "flesh out" the promises, to work out his own salvation with fear and trembling, then he unstopped his father's wells and remembered their names. Then he dug wells of his own.
And, on the very day of Abimilech's departure, after he had gone, Issac's servants came to him and told him that the well they had just dug had produced water. Isaac called it "Sheba" which means "oath." Oath speaks of covenant.