OT:1961 hayah (haw-yaw); a primitive root [compare OT:1933]; to exist, (Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary.)

OT:834 'aher (ash-er'); a primitive relative pronoun (of every gender and number); who, which, what, that; also (as an adverb and a conjunction) when, where, how, because, in order that, etc. (Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary.)

Exodus 3:14 The Septuagint: Egoo eimi ho Oon. Greek: Egoo (NT:1455) eimi (NT:1491) ho (NT:3543) Oon (NT:5541), "I am He who exists." It is in the present indicative active form of the verb “to be,” meaning, what is true of His being before is true of Him today, that He has no change from eternity past to eternity future.

He, the God) is the self- existing, self- sufficient one, He is the cause of all things. As some translate it to "I will be what I will be," or “O will be whatever you need me to be” (somewhat of a veiled prophetic application of the savior coming to earth). The name expressed the nature and actions of God toward man. That He would manifest in deeds expressing His nature in His name.

This expressed God as an unchanging and eternal Being, the existing one. self-existent: He possesses life in of himself. He is eternal and unchangeable, and always the same, yesterday, to-day, and for ever. He is incomprehensible; YHWH (Yahweh) are of the root meaning underived existence.

In Exodus 3:15 He identifies himself as the God of your fathers, God of Abraham, God of Isaac, and God of Jacob. [Name ... memorial] The name signifies that by which God made Himself known, The name “I AM” expresses the fact that He is the infinite and personal God that is behind everything in history. The use of the name Yahweh would be in reference to the national covenant[s] into which He was about to enter with Israel (Exodus 6:7). Ex 6:1-9 “I will take you to me for a people, and I will be your God.” That He is going to fulfill his promises given in covenant to Abraham, Isaac and Jacob (Gen.12:1-3). God therefore told him His name, YHWH (OT:3068), by which He had made Himself known to Abraham at the making of the covenant (Genesis 15:7).

Reminding them that he is [the] Elohim that created and made covenant with man (Genesis 2), and will covenant with Israel. That they can wholly depend on him and his promises that were made. Thus he is called Yahweh Elohim, the one and only God, the creator of all things seen and unseen.

Exodus 3:15 "This is My name for ever, and My memorial unto all generations”