Or HaChaim on Genesis 24:60/אור החיים על בראשית כ״ד:ס׳

1 את היי לאלפי רבבה. "May you become thousands and myriads." The reason Laban stressed the word "you" was that he was aware that Isaac would continue the Abrahamitic tradition and found great nations. Although this fact itself was anathema to wicked people such as Laban, they preferred that Rebeccah would be the founding mother than any other wife Isaac might marry. We must accept the psychological fact that the wicked hate the righteous even if the latter are their own flesh and blood.