Jehovah
Behold, therefore I will stretch out mine hand upon thee, and will deliver thee for a spoil to the heathen; and I will cut thee off from the people, and I will cause thee to perish out of the countries: I will destroy thee; and thou shalt know that I am the LORD. Ezekiel 25:7
Jehovah, the God of Israel, promises that even the nations who mocked His people will come to know who He is. Latter-day Saints know Jehovah as the premortal Jesus Christ, the Lord of all nations and not only of Israel.
AttestedJehovah — the LORDHe speaks in the first person
How we know: the verse itself names Him