Why the answer is usually eight
The Bible never pauses to say, “Moses went up Sinai eight times.” Instead, Exodus tells the story one meeting at a time. When the separate journeys are followed through the narrative, the usual total is eight.
The first ascent comes when Moses goes up to God after Israel arrives at Sinai. He then brings God’s message down to the people and returns their response to the Lord. That return is often counted as the second ascent, even though the wording focuses on Moses bringing the people’s words back to God (Exodus 19:3; Exodus 19:7-8).
And Moses went up unto God, and the Lord called unto him out of the mountain, saying, Thus shalt thou say to the house of Jacob, and tell the children of Israel;
The meetings before the covenant
Moses goes up again when the Lord calls him to the top of the mountain, then comes down to warn the people not to press past the boundary (Exodus 19:20; Exodus 19:25). After the Ten Commandments are spoken, Moses draws near to the thick darkness where God is. Many counts treat this as another ascent or approach into God’s presence on Sinai (Exodus 20:21).
These early trips show the pattern of Moses serving as a mediator. He carries God’s words to Israel, and he brings Israel’s response before God. The mountain is not presented as a place for spiritual achievement. It is where God graciously makes himself known to his covenant people.
And the Lord came down upon mount Sinai, on the top of the mount: and the Lord called Moses up to the top of the mount; and Moses went up.
Going higher into the mountain
Next, Moses goes up with Aaron, Nadab, Abihu, and seventy elders of Israel. They worship from a distance and are given a remarkable vision of the God of Israel (Exodus 24:9-11). Soon after, Moses is called to come further up the mountain to receive the stone tablets and God’s instruction (Exodus 24:12-15).
Some people combine these two scenes into one extended visit because they occur close together. Others count them separately because Exodus first describes Moses ascending with the leaders, then receiving a fresh command to come up and entering the cloud. Counting them separately is part of how the total reaches eight.
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.
After the golden calf
The final two ascents come after Israel’s sin with the golden calf. Moses tells the people that he will go up to the Lord to seek atonement for their sin, and the narrative says that he returns to the Lord (Exodus 32:30-31). Then he climbs Sinai again with two new stone tablets, where the covenant is renewed (Exodus 34:4).
So, the common eight are the trips in Exodus 19:3, 19:7-8, 19:20, 20:21, 24:9-11, 24:12-15, 32:30-31, and 34:4. If you see a smaller number, it usually reflects someone joining closely connected scenes together rather than denying the events themselves.