Yaakov was extremely well connected to angels. He saw them in his dreams, he wrestled them at night, and he even sent them on missions. Last year I argued that the entire story of the spotted and speckled sheep was an instance of Yaakov reprogramming the angels of the sheep and goats with the spirit of the angels within the tree shoots.
In order to precisely change something, it is essential that we first understand it intimately. If we think of angels as a divinely-written software program, then Yaakov had to be able to “see” the code in order to alter it. How did Yaakov reach that state, where he could understand angels “on the inside”?
An angel is the spirit “under” the flesh – the motivating force behind all the non-human flora and fauna in the world. Yaakov dressed up as an angel; he wore the skins of recently-slaughtered goats as his outer skin, just as an angel does. He was seeing the world from an angelic perspective.
Yaakov behaved precisely like an angel as well. Angels are similar to computer programs in that they do what they are told to do, and they do not exercise free choice. Yaakov was doing what his mother instructed; he was on a mission, which he executed faithfully and without deviation.
The text suggests that Yitzchak sensed some of this. When Yaakov goes to his father, covered in goatskins, Yitzchak observes (Gen: 27:27), “See, the smell of my son is like the smell of a field which the Lord has blessed.” The Hebrew word for “smell” (Reiach) is very similar to the word for spirit (Ruach). A blessed field is one full of plants and animals, a field which is equally full of angels (since every blade of grass has its own angel). Yitzchak detected in his son the presence of angelic spirit. It takes one to know one: Yaakov understood angels because he impersonated one!
From that point on, Yaakov had a sensitivity for angels, and as shown with Lavan’s flocks, he seemed to have especially talent for handling the angels associated with goats and sheep, a talent that may well have come from his own experience wearing their skins.
P.S. I also wanted to share a neat thought from Shlomo Berkowitz. He explains that a reason Yaakov had to marry Leah is because Leah had been destined for Esau; when Yaakov got his brother’s blessing, his brother’s wife was part of the package.