Or HaChaim on Exodus 3:13/אור החיים על שמות ג׳:י״ג

1 הנה אנכי בא אל בני ישראל, "When I come to the children of Israel, etc." At this point Moses had agreed in principle to accept the mission, conceding that the arguments he had voiced previously had now become irrelevant. However, he needed accreditation as a prophet in order to make the Israelites accept him as such. As soon as he would come to them they would ask him to identify himself by revealing the name of the G'd Who he claimed had spoken to him. We find that whenever G'd began to speak to the patriarchs He identified Himself by stating His name (compare Genesis 15,7; 17,1; 28,13). Moses wanted to know which of G'd's names he was to mention when he would come to the Israelites. Moses had been wondering that seeing G'd had identified Himself to him as "the G'd of your father Abraham, the G'd of Isaac, and the G'd of Jacob" without adding any other attribute as part of His identification, whether he should similarly identify G'd to the children of Israel when they would ask him who had communicated with him and had appointed him as their redeemer. Did G'd really think that this would suffice as an identification for the people to accept Moses as their leader?

2Moses implied that inasmuch as both he and the Israelites were already familiar with that aspect of G'd, in what way was Moses better or more intimate with G'd that they should believe he was a prophet sent on such a great mission? On the other hand, if Moses were to claim that the name of the G'd in whose name he had come was one that was unfamiliar to them, why would such a name carry any weight with them at all? I have seen many different commentaries on this verse, but I do believe that any person with an ounce of common sense will appreciate the way I have presented the problem Moses poses here. At this stage Moses most certainly did not ask G'd to provide him with a miracle he would be entitled to perform in order to prove that his claim was not spurious. You will note that G'd told Moses to tell the Israelites that He had identified Himself as אהיה. It is true that this was an attribute that G'd had never employed in His communications with the patriarchs. Moses realised now that as a true messenger he would never presume to interpret something G'd had said without first making certain that he had understood G'd correctly. No doubt Moses had been familar already with more than one attribute of G'd. However, he did not dare to convey to the people something he himself thought G'd had meant without checking. It is also possible that this verse merely reflects Moses' curiosity to learn more about the attribute G'd presently employed when speaking with him.