Transliterated as "Ehyeh asher Ehyeh"

Moses' problem was not that he did not know how to identify God. Moses already identified God's name as YHVH (pronounced "Yahweh" or "Jehovah"). Moses' problem was that if he returns, as a coward exile shepherd with no rights or authority in Egypt, he had no chance of success. However, God told him that He as the eternal God of their forefathers is sending Moses with His "name" (authority) to deliver a message from Him.

Then Moses said to God, “Indeed, when I come to the children of Israel and say to them, ‘The God of your fathers has sent me to you,’ and they say to me, ‘What is His name?’ what shall I say to them?”
And God said to Moses, “I AM WHO I AM.”
And He said, “Thus you shall say to the children of Israel, I AM has sent me to you.’ ”
Moreover God said to Moses, “Thus you shall say to the children of Israel: ‘The LORD (YHVH) God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has sent me to you. This is My name forever, and this is My memorial to all generations.’ Go and gather the elders of Israel together, and say to them, ‘The LORD God of your fathers, the God of Abraham, of Isaac, and of Jacob, appeared to me, saying...” -- Exodus 3:13-16 (NKJV)

The original Hebrew is transliterated as "e'heyeh aser' e'heyeh". The most basic translation of those words are "I am who I am", but it could also mean "I will be what I will be", "that which will be, I am, that which will be".

In other words, to a people group that are surrounded by Egyptian gods, God introduced Himself as the true self-existent unique uncreated eternal God. These are attributes that the Egyptian gods cannot claim and cannot compete against.

Some belief that this name is also related to the name "Who was and Who is and Who is to come" found in Genesis 3:14; Isaiah 48:12; Revelation 1:8; Revelation 4:8; Revelation 11:17; Revelation 16:5