The Tefillin contains four separate perashiot paragraphs all of which discuss the Mitzvah of Tefillin to tie them to your arm and put them on the head. However, we only repeat two of these constantly, Shema Yisrael and Vehaya Im Shamoa. This is because it states “Veshinantam” only here. That is to say that one needs to know these two Perashiot better. (Sifrey)
The Midrash Tanchuma embellishes this concept of learning the Torah through sharpening. It states that one only studies Oral Torah by very hard work. One who is lazy cannot understand the Oral Torah. The written Torah speaks generally while Oral tradition discusses many details; the written Torah is a fairly small book while the Oral Torah is infinite.
The Midrash Tanchuma itself compiles two separate Midrashic Commentaries about how the Jewish people accepted the Torah. One states that Beney Yisrael accepted the Torah by stating “Naaseh Venishma – We will do and listen” That is to say that Beney Yisrael said we will follow the Torah and understand it after we follow the commandments. However, they say that G-d actually lifted up mount Sinai and held it above the Jewish people. He said, “If you accept the Torah, great. If you don’t want it then you will all be buried there.” Midrash Tanchuma says that Jews said, “we will follow then listen” refers only to the Written Torah. The incident about the mountain being held above them refers to Oral Torah as it is said, “They stood at the bottom of the mountain.”(Warsaw Tanchuma Noach 3 – Shu”t) The Gemara does a play with the words. It is asked what does the phrase “Veshinantam Lebanecha” mean? They answer that the text needs to be read with a slight difference, read it “veshilashtem” study the Torah in thirds. You should divide your Torah study in the following way one third should be studying Written Torah, Mishna and Gemara.