English: What are we dealing with? If eating matzah — that is already written. If to say it begins on the fourteenth — that is already written until the twenty-first in the evening. Rather, if it is not needed for eating matzah, apply it to removal of chametz — from here, biur chametz on the fourteenth is from the Torah.
Type of Learning
Redirect of the verse from matzah-eating duration to Torah-level biur on the 14th.
What Is Learned
Destroying chametz on the fourteenth has a Torah basis drawn from this verse.