"After Isaac finished blessing him, and Jacob had scarcely left his father's presence, his brother Esau came in from hunting. He too prepared some tasty food and brought it to his father. Then he said to him, 'My father, please sit up and eat some of my game, so that you may give me your blessing.' His father Isaac asked him, 'Who are you?' 'I am your son,' he answered, 'your firstborn, Esau.' Isaac trembled violently and said, 'Who was it, then, that hunted game and brought it to me? I ate it just before you came and I blessed him - and indeed he will be blessed!'" NIV translation
Just after Jacob left, Esau came in with the food to get his father's blessing. Isaac found out that he had been tricked and was shaken. Isaac knew that, once the words of blessing were expressed, God would hear and they would be fulfilled. The same is true for us, as Christians. We have the same type of relation to God as Isaac did in that, if we express something in words, we can be sure that God hears and will act in our best interests.
"When Esau heard his father's words, he burst out with a loud and bitter cry and said to his father, 'Bless me - me too, my father!' But he said, 'Your brother came deceitfully and took your blessing.' Esau said, 'Isn't he rightly named Jacob? This is the second time he has taken advantage of me: He took my birthright, and now he's taken my blessing!' Then he asked, 'Haven't you reserved any blessing for me?'" NIV translation
Esau desperately asked for a blessing and blamed Jacob for stealing it from him. He mentions his birthright but basically says that Jacob had stolen it as well. Jacob had not stolen the birthright as it had been sold to him by Esau.
The birthright and the blessing were traditionally connected but Esau had hoped to separate them when he sold the birthright. The birthright had to do with spiritual leadership while the blessing had to do with material provision. Esau was not concerned with matters of God (the spiritual things) but desperately wanted the material things. Finally, he asked his father for the leftovers from the blessing.
In Christ, we have both the birthright and the blessing as He has promised us that He will provide what we need both spiritually and physically.