Shemot (Exodus): Mishpatim > Ch 24
G-d tells Moses to ascend to Mt. Sinai with Aaron, Nadab, Abihu and 70 elders of Israel
G-d told Moses:
Come up to the Lord, you and Aaron, Nadab and Abihu, and seventy of the elders of Israel, and prostrate yourselves from afar. And Moses alone shall approach the Lord but they shall not approach, and the people shall not ascend with him.
Moses tells people G-d’s commandments and the people agree to follow them
Moses told the people all the words of the Lord and all the ordinances, and all the people answered in unison and said, "All the words that the Lord has spoken we will do."
Moses builds an altar, brings offerings, reads the Book of the Covenant to the people and sprinkles them with blood to mark the covenant
Moses wrote all the words of the Lord. And he arose early in the morning and built an altar at the foot of the mountain and twelve monuments for the twelve tribes of Israel. And he sent the youths of the children of Israel, and they offered up burnt offerings, and they slaughtered peace offerings to the Lord, bulls. And Moses took half the blood and put it into the basins, and half the blood he cast onto the altar.
And he took the Book of the Covenant and read it within the hearing of the people, and they said, "All that the Lord spoke we will do and we will hear." And Moses took the blood and sprinkled [it] on the people, and he said, "Behold the blood of the covenant, which the Lord has formed with you concerning these words."
Moses, Aaron, Nadab, Abihu and 70 elders of Israel ascend to Mt. Sinai
Moses, Aaron, Nadab and Abihu, and seventy of the elders of Israel ascended to Mt. Sinai
They perceived the G-d of Israel, and beneath His feet was like the forming of a sapphire brick and like the appearance of the heavens for clarity. And upon the nobles of the children of Israel He did not lay His hand, and they perceived G-d, and they ate and drank.
Moses stays on the mountain for 40 days & nights. G-d gives Moses the stone tablets with the Law and the commandments
G-d told Moses,
Come up to Me to the mountain and remain there, and I will give you the stone tablets, the Law and the commandments, which I have written to instruct them.
Moses and Joshua, his servant, arose, and Moses ascended to the mount of G-d. And to the elders he said, "Wait for us here until we return to you, and here Aaron and Hur are with you; whoever has a case, let him go to them." And Moses went up to the mountain, and the cloud covered the mountain.
And the glory of the Lord rested on Mount Sinai, and the cloud covered it for six days, and He called to Moses on the seventh day from within the cloud. And the appearance of the glory of the Lord was like a consuming fire atop the mountain, before the eyes of the children of Israel. And Moses came within the cloud, and he went up to the mountain, and Moses was upon the mountain forty days and forty nights.
So Moses and Joshua, his servant, arose
I do not know what business Joshua had here, but I would say that the disciple [Joshua] escorted his mentor [Moses] until the place of the limits of the boundaries of the mountain, for he was not permitted to go past that point. From there Moses alone ascended to the mountain of G-d. Joshua pitched his tent and waited there for forty days. So we find that when Moses descended, “Joshua heard the voice of the people as they shouted” (Exod. 32:17). We learn [from there] that Joshua was not with them.
He was Miriam’s son, and his father was Caleb the son of Jephunneh, as it is said: “and Caleb took to himself Ephrath, and she bore to him Hur” (I Chron. 2:19). Ephrath was Miriam, as is stated in Sotah (11b).