You know that I have served your father with all my strength,
yet your father has cheated me and changed my wages ten times. But God did not permit him to harm me.
In the many years that Jacob had worked for Laban, he had a tough time. First he agreed to work for 7 years so that he could marry Rachel and then Laban swapped his daughters so that he ended up marrying Leah instead, then he had to work a further 7 years to marry Rachel.
Laban consistently deceived Jacob, and attempted to cause him harm by changing his mind and their agreements so many times, but as he did, God protected Jacob from coming to harm. Just before these verses we see God at work in the situation in that which ever marked cattle Laban said Jacob could have, God caused to prosper.