"And it was when the camels finished drinking, Eliezer took a golden nose ring, its weight a Beka, and 2 bracelets on her arms weighing 10 golden Shekel. Rashi tells us, the Beka weight was an allusion to the Shekalim of Klal Yisroel - the half shekel donated by Klal Yisroel for the Beis HaMikdash. The 2 braclets were an allusion to the 2 Luchos - and the weight of 10 shekel, alluded to the Aseres HaDibros which were written on them.
Why was it necessary at this time for Eliezer to hint to Rivka concerning these future events? The Maharal answers that Eliezer was telling Rivka that the world stands on 3 things - Torah, Avodah and Gemilus Chasadim. I see that you are very accomplished in acts of Gemilas Chesed. However, to be one of the foundations of Klal Yisroel you must also excel in Torah and Avodah. Torah, which was represented by the 2 bracelets weighing 10 shekel - alluding to the Luchos. Avodah, which was represented by the Beka - used to purchase the Korbonos for the Beis HaMikdash.