Why did Eliezer suddenly run towards Rivkah?
Rashi says that the water rose to meet her. If so, why, in Pasuk 20, did she have to draw for all the camels? Why did the water not continue to rise by itself?
Rav Chavel on the Ramban (citing the Kedushas Levi) and Oznayim la'Torah: The water rose the first time when Rivkah drew for herself, 1 but not the second time, when it was in order to perform the Mitzvah of Chesed, which she had to do herself. 2
Oznayim la'Torah: Because she was a Tzadekes.
Others add that the second time was a test on her Midah of Chesed, which would have been meaningless had she not drawn the water personally, or in order to receive more reward, as the Mishnah writes in Avos at the end of chap. 5 - 'L'fum Tzara Agra! (The reward is according to the effort!)' - Oznayim la'Torah.
Eliezer said that he will ask her to tilt her jug, and he will drink. Why did he request now only "Hagmi'ini" (merely one swallow)?
Ohr ha'Chayim: He saw that the water rose for her
Ha'Emek Davar (18): However, she took down her jug so he could drink as much as he wants.