What does "Aseres Monim" mean?
Targum Onkelos: It means simply ten times.
Rashbam: Even assuming that literally, "Monim" means ten times, it is an exaggeration, and what it really means is very often.
If Lavan really changed his wages so often, why did the Torah not mention it at the time?
Ramban: Such is the way of the Torah, to leave the obvious to the imagination, or to mention it in one place but not in the other. 1
Ramban: Just as we find that, earlier (30:15), it does not explicitly state that Leah gave Rachel the Duda'im.
What is "Hesel Bi"?
Ohr ha'Chayim: Lavan saw how many were born with appearances that Yaakov receives, so he would stipulate one way before the animals became pregnant, and change the terms after they were pregnant.
Ha'amek Davar: Since he removed everything with white, I was forced to use sticks!
QUESTIONS ON RASHI
Rashi writes: "'Ten counts' - [And] a 'count' is no less than ten." Why is this so?
Gur Aryeh: One who is counting usually counts to ten, and then begins counting (the units) again at one. "Ten counts" means ten sets of ten, i.e. 100.
Rashi writes: "'Ten counts' - [And] a 'count' is no less than ten." If so, why didn't Yaakov explicitly say, '100 times'?
Gur Aryeh: Lavan kept shifting Yaakov's wages in exactly that manner - in ten cycles of ten. After claiming to owe Yaakov the animals that were ringed, speckled, etc. in ten different varieties, he returned to his original claim of the ringed animals. Lavan did so in spite of the disgrace in such a claim; he could no longer say that he had made a mistake. 1
For example, Lavan could no longer say that he had made a mistake by offering ringed animals, for it was the second time he was offering them! (EK)