Yitro 5775

The first of the Ten Commandments states that Hashem is our G-d Who took us out of Egypt from the houses of slaves. Based on the extra phrase of "houses of slaves", the Kedushas Levi brings up the reason why the Jews weren't given the Torah before they were redeemed. One who worships out of fear is called a slave; one who worships out of love is called a child. If Hashem had given us the Torah in Egypt, we would've accepted it out of fear in the form of slaves. Once we were redeemed, we were able to accept it out of love as children. That is why the verse emphasizes "slaves;" Hashem gave us the ability to worship him out of love.

Yitro 5773

There is a famous Midrash based on 19:17 saying that Hashem lifted Mt. Sinai on top of Bnei Yisroel and He threatened them to accept the Torah or they will destroyed. The Kli Yakar explains that Bnei Yisroel was never forced to accept the Torah; they had already agreed to accept anything Hashem told them to do (19:8). Rather, Hashem was telling them that not keeping the Torah will be as if one is dead in this world. Keeping the Torah guarantees life in this world and the next world.