The Plain Meaning and the Seal
On the law of the slave who stays, the Gaon explains why the Oral Torah sometimes overrides the plain reading of a verse, and why we still must know that plain reading.
Discussing the verse that speaks of bringing the slave to the door or to the doorpost, the Gaon observes that the plain meaning would seem to make the doorpost equally valid, yet the halachah overrides the plain meaning of the verse. This, he says, is so in most of this parshah and in several others. He sees in it the greatness of our Torah SheBeal Peh, which is a halachah from Moshe at Sinai, and which turns the plain text the way clay takes the shape of a seal pressed into it. The conclusion he draws is that one must also know the plain meaning of the Torah, because only then can he recognize the seal that was pressed into it and understand what the halachah has done.
Source: Aderet Eliyahu, Exodus 21:6 (on the words 'or to the doorpost')
When you learn something this week, a halachah, a pasuk or a piece of Chassidus, take a minute to ask what the plain words say before you look at the explanation. Read the sentence slowly and notice what it seems to mean, and only then see how Chazal or the commentaries lead us further. Knowing the starting point lets you appreciate the journey. The Gaon wanted every talmid to see both the clay and the seal, and so to value the Torah more.