Moshe was shepherding sheep for his father-in-law Jethro when he saw a burning bush which was not being consumed by the fire.When he heard the utterance “I am the G-d of your father, Moshe hid his face.R’ Munk quoted from Rambam who wrote that Moshe was humble and modest and was prepared to wait patiently as his knowledge of G-d advanced step by step.R’ Munk also quoted R’ Bachya who wrote that fear of G-d is the beginning of wisdom.
G-d told Moshe that He was aware of the suffering of the Jewish people and that He would bring them out of Egypt and bring them to Canaan. He wanted Moshe to go to Pharaoh to warn him of the impending departure. Moshe asked G-d how he wanted to be known to the Jewish people.G-d answered “I Shall Be As I Shall Be”, “tell the Children of Israel “I Shall Be has sent me to you”, the G-d of Avraham, the G-d of Yitzchac and the G-d of yaacov has despatched me to you. This is My Name forever, and this is My rememberance to you from generation to generation”.
R’ Munk quoted Rambam who explained that “Eheye”, I Shall Be, is derived from “Haya” to exist, denoting an existence without any reason or cause. G-d’s existence is His true essence and cannot be attributed to and reason or accident.(1) G-d’s Being is of a purely spiritual nature, He is free from all material contingencies and His attributes are constant and invariable. Another explanation is that G-d will be with the Jewish people in their present and future troubles. “Let them pray to Me and I shall answer them”.
The other way that G-d directed Moshe to denote His existence was through “the G-d of your forefathers”. The knowledge of G-d could be acquired by ancestral tradition since the philosophical significance of G-d’s Names would be difficult to grasp. Philo explained that the path to the knowledge of G-d for Avraham was through personal reflection, for Yitzchak it was through the observation of nature, and for Yaacov it was through the study of the Divine laws.
(1) The Guide to the Perplexed. Rambam.