The Siddur
When we speak about the Siddur, we are not only discussing the mere Avodah of Tefillah. The understanding of the Siddur itself is a major objective. The Siddur contains in it almost all of the general principles of the Torah, including the Chovos Halevovos and Ahavas and Yir’as Hashem. Thus, the study of the Siddur is actually an important part of Limud Hatorah, as well as a way to attain true Greatness of Soul and Da’as Hashem.