Albert Barnes Commentary Exodus 3:15

"And God said moreover unto Moses, Thus shalt thou say unto the children of Israel, Jehovah, the God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath sent me unto you: this is my name forever, and this is my memorial unto all generations." — Exodus 3:15 (ASV)

The Lord God ... - Better, Jehovah יהוה yehovah — God of your fathers, God of Abraham, God of Isaac, and God of Jacob. It corresponds exactly to the preceding verse, the words “I am” and “Jehovah” (Yahweh) being equivalent. This name met all the requirements of Moses, involving a two-fold pledge of accomplishment; the pledges of ancient benefits and of a new manifestation.

Name ... memorial - The name signifies the means by which God makes Himself known, the memorial the means by which His people worship Him.