Rashi (24:42) writes, אבות עבדי של שיחתן יפה כפולה אליעזר של פרשה שהרי ,בנים של מתורתן המקום לפני ברמיזה אלא נתנו לא תורה גופי והרבה ,בתורה , "The conversations of the servants of the Avos are more beloved before Hashem than the Torah of their sons, for the section dealing with Eliezer is repeated in the Torah, whereas many fundamentals of the Torah were only hinted."
Rav Shach zt'l explained in the name of the Chofetz Chaim zt'l that one of the lessons we learn from the אבות עבדי של שיחתן, the conversations of the servants of the avos, is that they knew clearly that nothing can be achieved without Hashem. One would think it would be easy for Yitzchak to find his shidduch. Yitzchak was the holiest person in the world, the son of Avraham Avinu, almost sacrificed as a korban, and he was extremely wealthy as well. (Avraham gave Yitzchak his entire wealth; see Rashi 24:10). With such an impressive resume, we assume that it was simple and easy for Yitzchak to find his shidduch. But Eliezer davened (24:12) חסד ועשה אברהם אדוני עם, "Perform kindness with my master, Avraham." He understood that without Hashem's kindness, the shidduch wouldn’t occur.
The Midrash writes on this pasuk, "Everyone needs chesed. Even Avraham, about whom it was said that chesed came to the world for him, needed chesed, as it states אברהם לאדוני חסד עשה, "Perform chesed with my master, Avraham."
The Chidushei HaRim zt'l adds that Eliezer learned from his rebbe, Avraham Avinu, that Hashem doesn't owe anyone anything. When he prayed for Yitzchak's shidduch, he prayed that Hashem should do chesed with Avraham. He didn't request that Hashem help Avraham find a shidduch for his son because of Avraham's many merits. The Chidushei HaRim explains that Avraham Avinu taught his talmidim that Hashem doesn't owe us anything. Everything we receive from Him is chesed.
