The Chesed of Rivkah:
Sefer Kedushas Levi writes that when a person does a mitzvah, he creates a spirit of holiness that affects the entire world. If a person does chesed, for example, he brings down Hashem’s middah of chesed to provide kindness to the entire world. The same applies to all mitzvos.
Avrohom Avinu was the epitome of chesed. Every act he did was permeated with chesed. Therefore, he brought the middah of chesed to this world, and this inspired everyone else, including Rivkah, to do chesed.
Accordingly, Eliezer said that he was waiting for a girl who would do chesed for him. But what caused her to do chesed? It was because she was “with my master”. The fact that she was in this world with Avrohom influenced her to do chesed for others.
Avrohom’s Neshama Is In Every Jew Who Does Chesed:
Early tzadikim state that when a person does chesed, the neshama of Avrohom Avinu, the pillar of chesed, enters his body. This is as is stated in Sefer Tiferes Shlomo (Parshas Pinchos) that when a person does a mitzvah l’shmah, the neshama of a tzadik from a previous generation enters his body. In this vein, it is known that the author of Sefer Medrash Shmuel said that the neshama of Rav Pinchos ben Yair came into his body when he did an act of tzedakah.
It can be said that this is hinted to from the words of this pasuk. Eliezer said that “she will do chesed with my master, Avrohom.” This can be understood to mean that when she does chesed, she will be with Avrohom because his neshama will join with her for this act.
