What does Genesis 27:15 mean?
Isaac is attempting to pass his blessing on to Esau, his firstborn twin son. Isaac's wife, Rebekah, overheard this plan (Genesis 27:6–10) and schemed with Jacob, the younger twin she preferred (Genesis 25:28). This plot relies heavily on Isaac's blindness (Genesis 27:1). Jacob makes no effort to resist, only asking how to avoid being caught (Genesis 27:12).Here, Rebekah's scheme to trick her husband Isaac into giving the family blessing to Jacob instead of Esau has reached its critical moments. She has prepared the delicious meal, and Esau has not yet returned. All that remains now is to disguise Jacob, making a convincing enough version of Esau to deceive his blind father long enough to get the blessing from him.
This starts with the clothes, and Rebekah has access to Esau's best garments. She puts Jacob into them. Though Isaac is blind, the real purpose of this deception is the difference in their smell. Beyond that, though, Jacob is still smooth-skinned, while Esau is famously hairy (Genesis 25:25). Rebekah will have an answer for that in the following verse.