There is a problem with the widely accepted etymology of the word YHWH being from the Hebrew verb root for “to be.” In ancient times, the Hebrew root for the word “to be” was HWY, and if the widely accepted etymology based on the verb "to be" (because of Exodus 3:14) where the origin of the name of YHWH, then it would have likely been spelled YHWY. Also, Exodus 3:14 speaks in the first person, 'eyhah', which is mostly translated as "I am" or, more accurately "I’ll be" (in the cohortative, not future tense) by many translators. The word "Yahweh" is a third person form of the verb "to be" in Hebrew, or “He is.” It is a far leap from the first person cohortative to the third person imperfect. Actually, this third person form of “to be” is not found anywhere in the Hebrew scriptures for the root hwh. The more recent form of this root hyh is mostly used, and is current in Modern Hebrew also.
So, what does YHWH mean, and what was Moshe’s point in using the first person cohortative of the verb “to be” to refer to God? As usual, the answer is found in the historical context rather than the pure grammar of the scripture.
A clue comes in Exodus 15:2, where Moshe is quoted as referring to Yahweh by his true name (emphasis added):
YaH is my strength and song, And he has become my salvation: This is my God, and I will praise him; My father's God, and I will exalt him.
This proper name of God (non-descriptive) is given in Psalm 68:4:
Sing to God, sing praise to His name; lift up a song for Him who rides in the deserts, by His name YaH; yes, exult in His presence. His name is YaH.
The word YaH (Hebrew YH) is a cognate of the Akkadian word EA. They are pronounced roughly the same but the Akkadian word EA was pronounced almost precisely the same as the first-person cohortative form of the Hebrew verb to be `eh'yeh (Hebrew 'HYH).
The Akkadian word EA is derived (according to the American Heritage Dictionary) from the Old Akkadian *hayy meaning "living" or "life causer." (It's pronunciation is Eh-Ya). To Akkadian speakers of the Anatolian plateau, EA was the God of living water - the "life-giver God." The Hebrews adopted this word from the early pre-Armenians. (Note that the name Eve (life giver) is derived from the same root.)
Exodus 3:14 says:
vayo`mer `elohiyM `el ´ moSheh `eh'yeh `aSher `eh'yeh vayo`mer coh To`mar liV'nay yiS'ra`al `eh'yeh Sh'laHaniy `alaykeMNow, the Hebrew word 'aSher is a relative pronoun and is used to introduce a relative clause (in this case, the clause "I'll be" substituted for the normal "I am" because it creates a wordplay.). So the proper translation would be:
"..and God said to Moshe, "Yah [is] who I am!" and he said "You will say this to the sons of Israel, 'Yah has sent me to you.'"Interestingly, a very similar wordplay appears in the Babylonian epic Enuma Elish:
"su-u ki-ma ia-a-ti; e-a lu-u sum-su" or "He is the same as I am; Ea is his name."