Exodus 20:15 declares clearly and emphatically, “Thou shalt not steal.” It is indeed a sin to steal but Jacob did NOT steal Esau’s birthright, even though he did steal his blessing. Let’s talk about the “birthright” first and then we’ll consider scriptures dealing with the “blessing.” In Genesis 25:29-34 we read, “Now Jacob cooked a stew; and Esau came in from the field, and he was weary. And Esau said to Jacob, ‘Please feed me with that same red stew, for I am weary.’ Therefore his name was called Edom. But Jacob said, ‘Sell me your birthright as of this day.’ And Esau said, ‘Look, I am about to die; so what is this birthright to me?’ then Jacob said, ‘Swear to me as of this day.’ So he swore to him, and sold his birthright to Jacob. And Jacob gave Esau bread and stew of lentils; then he ate and drank, arose, and went his way. Thus Esau despised his birthright” (NKJV). There are two lessons in this sad story. As I said Jacob did not steal his brother’s birthright, but he did take advantage of Esau’s weak condition. In verse 23 of this chapter we learn that God had told Jacob’s mother before the twin boys were born that “the elder shall serve the younger” and perhaps Jacob thought divine providence was at play here and that his acquiring the birthright in this way was one step towards that end. He was surely wrong in dickering with his brother as he did, but Esau’s failure was even greater. We read that “Esau despised his birthright.” What is a birthright? A birthright was a special honor given to the firstborn son making him the “head of the household” and “the heir to his father’s estate.” It was a rich blessing that Esau was willing to sell for one simple meal! He had said, “Look, I am about to die; so what is this birthright to me?” but the truth is he wasn’t starving to death; he was simply “weary.” It showed that he valued his “physical appetite” more than he did his “spiritual blessings.” Hundreds of years later God had this to say about Esau in Hebrews 12:16, “That there be no immoral or godless person like Esau, who sold his own birthright for a single meal” (NASB).

The story of Jacob stealing Esau’s blessing is found in Genesis 27:1-36, which I would encourage you to read. In verses 1-4 Isaac told Esau, who was a hunter, to go shoot some game and bring it to him and he would bless him before he died. In verses 5-17 Rebekah, who had heard Isaac speaking to Esau, devised a plan where Jacob would pretend to be Esau and trick Isaac, who was nearly blind, into giving him the blessing instead. Like Jacob, she too must have thought that in order for the prophecy of Esau serving Jacob to come true, they would have to resort to this scheme.   In verses 18-29 the deception was carried out and Isaac, who was fooled into thinking Jacob was really Esau, blessed him with material wealth, leadership, and protection from enemies. From verses 30-36 we see the return of Esau from the field and Isaac learns that he was indeed deceived by his younger son. He had this to say to Esau about his brother Jacob in verse 35Your brother came with deceit and has taken away your blessing” (NASB).

Your question “Why did Jacob get blessed anyway?” is valid. Why didn’t Isaac revoke the blessing and give it to Esau? In verse 33, after Isaac had realized what had happened, he declared to Esau, “I ate all of it before you came, and I have blessed him—and indeed he shall be blessed.” Isaac knew that THE BLESSING COULDN’T BE RETRACTED! I believe he understood that his plan to bless Esau, as we saw in verses 1-4, was contrary to God’s plan for “the elder shall serve the younger.” He was tampering with God’s purpose and now he was willing to leave the blessing with Jacob. So, Isaac was wrong in wanting to bless Esau with prosperity and dominion instead of Jacob, and Rebekah and Jacob were equally wrong in deceiving Isaac, but God overruled and in His sovereignty Jacob got the blessing and the prophecy would be fulfilled.  (179.3)  (DO)