The fact that the emissary chose Rivkah is no news to us, because we have the advantage of living in a later generation when we are equipped with a Chumash to tell us how the story worked out.
But no matter when a person happens to consider the mission which Eliezer performed, they wonder why he used criteria that had to do with providing water at the well.
Discussing marriage, the Talmud offers a number of recommendations as to how to chose a wife, but drawing water doesn’t seem as important to the rabbis as it obviously was to Eliezer.
There is of course the expedient, pragmatic way of looking at the story. This reminds us that the episode took place after all in the parched Middle East where water is so essential for humans, animals and plants.
But there must be more to it than that. Eliezer was looking for character traits, and dealing with water and all it entailed helped him to make up his mind. What he saw in Rivkah was a person whose intelligent instinct told her what was needed; her ethical conscience told her how to be kind and helpful; her energy told her she had to exert herself.
Metaphorically, knowing that later generations would say, Ein mayim ella Torah – “’Water’ is a symbol of Torah” (Bava Kamma 17a), Rivkah realised that a good Jewish wife is dedicated to the continuance of Jewish knowledge and observance.
Eliezer chose well, and Jewish history owes him a huge debt of gratitude.