Musar zu Bereschit 31:15

To answer all this, it would seem that Jacob knew that obviously Lavan would not agree to give him his daughter without receiving a great gift, as it is written (Ibid. 31:15): "Does he [Lavan] not regard us [his daughters] as strangers"? [see Rashi] And it is known that our father Jacob became impoverished by Elifaz [the son of Esav] on the way. If so, he would certainly have to do slave labor for him in order to marry his daughter, as Isaac had commanded him, and as, indeed, occurred in the end. And Jacob was afraid to go down to him and to remain there. For he knew that Lavan was a deceiver, and that he would also want to drive him from the world, as the Torah testifies about him at the end, that he pursued him and desired to kill him, lest the G-d of Abraham aided and rescued him (viz. Ibid. 31:42). And [he knew that] his house, too, was full of idols and that he could not withstand such impurity without the merit of the holiness of Torah, and that in the house of Lavan it would not be possible for him to cleave to Torah.