What does Genesis 27:24 mean?

Jacob is trying to fool his father by impersonating Esau, his older brother. The reason for this fraud is to have Isaac grant his fatherly blessing to Jacob instead. The plan is actually a conspiracy between Jacob and his mother, Rebekah, who has supplied him with the food Isaac requested from Esau, Esau's clothes, and goat skins to mimic Esau's hairiness (Genesis 27:1–10). Even after feeling Jacob's goat-skin covered hands, Isaac, old and blind, still seems unconvinced and confused. He is ready to believe that Esau is before him with a meal of freshly killed and prepared game. He is ready to give Esau the blessing. He seems to sense something is still off though.

Finally, he just asks Jacob outright, "Are you really my son Esau?" Now Jacob commits to the lie fully: "I am." His attempt to deceive his father in order to steal the family blessing from his firstborn brother is complete. The following verse will show that Isaac decided to believe him. He is ready to eat the meal and give the blessing.

God is not without a sense of humor. Not long after this incident, Jacob will find out what it feels like to be cheated (Genesis 29). After that, God will pointedly force Jacob to identify himself before he can be blessed (Genesis 32:26–28).