Musar על סנהדרין 90:5

Remember that the first of the thirteen principles used for exegesis of the Torah, is the principle of כלל ופרט. [In our daily recitation of these thirteen principles, this one is listed as number four. Ed.] We are told there that the כלל, general rule, cannot include anything which has not been alluded to in the description of the פרט, the detailed example of what is meant by the כלל. It is common knowledge that these thirteen principles are not something conjured up by human intelligence, but that they are principles by which G–d operates both in areas visible to us, i.e. נגלה, and in domains that are completely hidden from us, i.e. נסתר. The overriding rule to remember is that the כלל, whole, does not contain anything which is totally foreign to the פרט, part. When it is part of the פרט, it is נגלה, revealed, visible, whereas when it is part of the כלל, it may remain hidden, invisible to our eyes or faculties. Our sages, when discussing aspects of the מעשה בראשית, the work of creation, have already said with regard to the creation of the physical universe that every little detail that would ultimately be revealed was already part of the matter created on the first day. As creation proceeded these various פרטים, details, were revealed and became functional day after day. Rashi has explained all this in his commentary on Genesis (Genesis 1,14, and 1,24). Philosophers called this first physical existence Hiyuli, the world's raw material. All other elements are derived from that matter called Hiyuli. Something parallel happened in the Celestial Regions. The original Cause, i.e. idea of G–d to create the universe, is what we call the כלל. All other thoughts and plans of G–d are פרטים, "details," by comparison.