ותמלא כדה ותעל
“She filled up her jug with water, and brought it up from the well.” (Bereishis 24:16)
Chazal tell us that when Eliezer saw the well water rising up to Rivkah, he knew he was in the company of someone special. The Rishonim explain that the Medrash knew this from the fact that the word ותשאב – to draw, is conspicuously missing the first time Rivkah drew the water. It is only used in the subsequent pasukim. The Rambam goes so far to say that this miracle only happened the first time, and not when she drew water for Eliezer and the camels. He does not offer a reason.
Perhaps it was just to help Eliezer realize that she may be the one. However, Reb Zalman Sorotzkin in his sefer Oznayim LaTorah explains it on a deeper level:
When Rivkah drew water for her family it was a mundane menial task. Thus, Hashem spared her the effort of bending down. However, when it came time to perform an act of chessed, she didn't want her efforts spared. To the contrary, every move, every drop of exertion, elevated this lofty act of kindness even more. Every extra effort spent, was all part of her mitzvah.
There's a short anecdote which complements this idea. The Vilna Gaon's wife and her friend were partners in many chessed projects. They made a pact that whichever would be niftar first, would come to the other in a dream and relay the happenings Above. The friend passed away first and appeared to the Gaon’s wife. She relayed that the cheshbonos [calculations] in heaven are awesomely accurate. Once when we were collecting, we went to the home of a potential donor, but they weren't home. As we were departing, you spotted them and we solicited the donation. We were both credited with that solicitation. Alas, you were received more reward than I, because you raised your hand to point towards them, to go over and solicit.
So, when we have the opportunity to exert ourselves while performing a mitzvah, let us do so happily; as the maxim goes לפום צערא אגרא – according to the pain is the reward, and learn from Rivkah, who understood the power of not only the mitzvah itself but the efforts expended in completing it as well! (Rabbi Chaim Yosef Kofman zt”l, Machsheves Halev)
