Charles Ellicott Commentary Exodus 3:14

"And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you." — Exodus 3:14 (ASV)

I AM THAT I AM. —It is generally assumed that this is given to Moses as the full name of God. But perhaps it is rather a deep and mysterious statement of His nature. I am that which I am. My nature, that is, cannot be declared in words, cannot be conceived of by human thought. I exist in such a way that my whole inscrutable nature is implied in my existence. I exist, as nothing else does—necessarily, eternally, really. If I am to give myself a name expressive of my nature, so far as language can be, let me be called I AM.

Tell them I AM has sent me to you. — I AM, assumed as a name, implies:

1. An existence different from all other existence. I am, and there is none beside me (Isaiah 45:6).
2. An existence out of time, with which time has nothing to do (John 8:58).
3. An existence that is real, all other existence being shadowy.
4. An independent and unconditioned existence, from which all other existence is derived, and on which it is dependent.