The Book of Deuteronomy presents a fundamental question. It begins: "These are the words which Moses spoke," i.e., it collects Moses' farewell addresses to the Jewish people, statements which he made on his own initiative. On the other hand, one of the fundamental principles of Jewish faith is that every word in the Torah, including the Book of Deuteronomy is "the word of G-d," endowed to us by Divine revelation.
One of the resolutions offered to this difficulty points to the utter identification of Moses with G-d. For this reason, in these addresses Moses occasionally uses the pronoun "I" when speaking of G-d. For example, in the second portion of the Shema, it says: "I will grant your rains in their season." "I" refers to G-d, but was spoken by Moses. As our Sages commented: "The Divine presence spoke from Moses' throat."
This motif is not only limited to Moses. Our Sages comment: "Every new Torah insight developed by an experienced scholar was given to Moses on Mount Sinai." Although the person labored to bring out these new ideas, they are not his own, but G-d's. Every person has the ability to transcend the human realm and reveal Divine truth.
What is the key to discovering such insights? Identifying one's "I" with G-d and not with one's own self. When a person is preoccupied with self-concern - what I want, and what I think is right - that is what he will think and speak about. When, by contrast, he is able to step beyond his individual concerns, he is able to appreciate - and share with others - G-d's wisdom.