[A]nd they saw the God of Israel. Under his feet there was something like a pavement of sapphire stone, like the very heaven for clearness. God did not lay his hand on the chief men of the people of Israel; also they beheld God, and they ate and drank. The Lord said to Moses, "Come up to me on the mountain, and wait there; and I will give you the tablets of stone, with the law and the commandment, which I have written for their instruction." So Moses set out with his assistant Joshua, and Moses went up into the mountain of God. To the elders he had said, "Wait here for us, until we come to you again; for Aaron and Hur are with you; whoever has a dispute may go to them." Then Moses went up on the mountain, and the cloud covered the mountain. The glory of the Lord settled on Mount Sinai, and the cloud covered it for six days; on the seventh day he called to Moses out of the cloud. (NRSV 24:10-16)
And they saw the God of Israel: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness. And upon the nobles of the children of Israel he laid not his hand: also they saw God, and did eat and drink. And the Lord said unto Moses, Come up to me into the mount, and be there: and I will give thee tables of stone, and a law, and commandments which I have written; that thou mayest teach them. And Moses rose up, and his minister Joshua: and Moses went up into the mount of God. And he said unto the elders, Tarry ye here for us, until we come again unto you: and, behold, Aaron and Hur are with you: if any man have any matters to do, let him come unto them. And Moses went up into the mount, and a cloud covered the mount. And the glory of the Lord abode upon mount Sinai, and the cloud covered it six days: and the seventh day he called unto Moses out of the midst of the cloud. (KJV 24:10-16)
Yowza. The God of Exodus is definitely a physically present character. In later books of the Bible, God asserts himself in other ways that give him a different type of reputation. Here, you see the guy. We can imagine that image would be pretty convincing.