Pashas Chayei Sara: Sforno -Rivka, Not Even A Thank You “Vayehi Kaasher Kilu HaGmalim Lishtos Vayikach HaIsh Nezem Zahav” (Chayei Sara 24:22), after the camel finished drinking Eliezer gave Rivka jewelry. Why does the Torah point out that it was only after the camel finished drinking? Did Eliezer need to wait for the last sip before he knew Rivka was the right girl?
The Sforno answers that until the camels didn’t finish drinking, Eliezer did not know if the girl would want something in return. Maybe she had ulterior motives. Only after the job was completed and Rivka didn’t ask for anything in return, not a even a compliment or a thank you, did Eliezer understand that she was a true Baalas Chesed. True Chesed is the love of helping others without the slightest sense of our own ego.
From Revach.net