The Sforno on this pasuk is bothered by the need for the Torah to inform us that Lavan blessed his children and grandchildren: “Our Sages have already said, ‘Even the blessing of a common man should not be treated lightly’ (Megillah 15a). However the Torah tells us of Lavan’s blessing to his daughters to teach us that a father’s blessing is, without a doubt, given with all his soul, and is worthy to be accepted (effective) reflecting the tzelem Elokim (image of G-D) within the [father] who blesses, similar to what [Yitzchok mentioned earlier when he wanted to bless Esav,] ‘That my soul may bless you’ (Breishis 27:4). (Click here for Hebrew text.)
Rabbi Raphael Pelcovitz explains the connection to the tzelem Elokim (image of G-D): “The phrase Tzelem Elokim (Breishis 1:27), is explained by the Sforno as meaning that man has the potential to understand G-D and perfect himself to the extent of reaching a level of G-Dliness and immortality. This power is hidden in his soul (nefesh), and when this force is released its impact is powerful. When a father blesses his children, the blessing emanates from the depth of his soul and therefore it is extremely effective. This is true whether it be a Yitzchok or a Lavan.”
It sounds like there is an automatic tendency or ability for a father to be tuned into his pure soul and to give everlasting effective blessings to his children. However if you look at the Sforno by Yitzchok it does not seem so simple. The Sforno explains why Yitzchok first asked Esav to prepare some delicacies for him before giving the blessings: “He asked for savory food so that (Esav) should occupy himself in the mitzvah of honoring his father so that the blessings are affective, for even though he did not recognize Esav’s great wickedness, nonetheless he did not feel him worthy to receive the blessing that he had in his heart to give him.” (Click here and here for Hebrew text)
Yitzchok wanted to give Esav the blessings but it would seem that it would not have come naturally if not for the meal he requested from Esav, even though there supposedly is this natural ability for a father to tap into his own soul and give an affective blessing to his son.
The Evil Lavan who just a day ago and even hours earlier was ready to kill his children and grandchildren in cold blood over his idols, was able to automatically be in sync with his holy, sublime soul to give blessings to his daughters and presumably his grandchildren with such an effect that it was worthy of mention in the Torah. So it obviously worked, as the Sforno is teaching us. But Righteous Yitzchok, one of our forefathers, a very holy person, considered hekdesh [literally holy] because of almost being sacrificed by the binding of Yitzchok, could not automatically give Esav his blessing and had to ask Esav to perform the mitzvah of honoring him? Indeed, Yitzchok knew that Esav excelled in that mitzvah, to ensure he could muster up his abilities to be attuned with his soul, so that the blessing will work. Why was it automatic for Lavan but not Yitzchok?
We must say that in fact Yitzchok, on the level he was on, certainly was in tuned with his soul and was able to control this ability to give blessings that work, but that he wanted to make sure Esav really earned it. In fact, the Sforno concludes that when Yitzchok told Yaakov to go to Lavan and get married there Yitzchok did give Yaakov a guaranteed blessing from the soul, for the Sforno says: “Because of this, when he blessed Yaakov later (before he left for Haran) he did not request him to bring savory food, but blessed him at once saying, ‘And G-D Almighty bless you’ (Brieshis 28:3), for he knew that he was worthy to be blessed.”
What this means is that a father giving a blessing to his children that works is not natural and automatic; so how did Lavan do it? This can be explained by the famous stories of mothers who lift up cars with one hand and save their baby from underneath with the other hand. It is possible to get a supernatural rush of energy at times, of immense passion or compassion, and to do things which are not humanly possible because the adrenaline causes such drastic measures.
Not only is this possible physically, but it is also possible spiritually and mentally.
Lavan, aware that this would probably be his last time seeing his children and grandchildren, had a supernatural inspiration of fatherly love and compassion which drove him to tap into his pure soul, his tzelem Elokim, bringing out altruistic blessings, which worked on his family.
The ability to tap into our purity and holiness, which Hashem endowed us with, is within every single human being no matter how far gone they are from the true source and it can potentially be tapped at any moment, pressing the right buttons or with the proper inspiration.