Israel's covenant with the Lord is confirmed with sacrifice and the sprinkling of blood on the people of Israel. Moses then is called by the Lord to go up on Mount Sinai to receive stone tablets of the Ten Commandments. He spends 40 days and nights with the Lord.
Like Christ in the desert at the beginning of His ministry, Moses begins his role as lawgiver through 40 days of fasting and prayer in the presence of the Lord. The blood sprinkled on the people of Israel foreshadows the blood of the New Covenant, the Blood of Christ, shed on the Cross and made present to us again at every Mass.
And he said to Moses: Come up to the Lord, thou, and Aaron, Nadab, and Abiu, and seventy of the ancients of Israel, and you shall adore afar off. And Moses alone shall come up to the Lord, but they shall not come nigh; neither shall the people come up with him.
So Moses came and told the people all the words of the Lord, and all the judgments: and all the people answered with one voice: We will do all the words of the Lord, which he hath spoken. And Moses wrote all the words of the Lord: and rising in the morning he built an altar at the foot of the mount, and twelve titles according to the twelve tribes of Israel.
And he sent young men of the children of Israel, and they offered holocausts, and sacrificed pacific victims of calves to the Lord. Then Moses took half of the blood, and put it into bowls: and the rest he poured upon the altar. And taking the book of the covenant, he read it in the hearing of the people: and they said: All things that the Lord hath spoken we will do, we will be obedient. And he took the blood and sprinkled it upon the people, and he said: This is the blood of the covenant which the Lord hath made with you concerning all these words.
Then Moses and Aaron, Nadab and Abiu, and seventy of the ancients of Israel went up: And they saw the God of Israel: and under his feet as it were a work of sapphire stone, and as the heaven, when clear. Neither did he lay his hand upon those of the children of Israel, that retired afar off, and they saw God, and they did eat and drink.
And the Lord said to Moses: Come up to me into the mount, and be there: and I will give thee tables of stone, and the law, and the commandments which I have written: that thou mayst teach them. Moses rose up, and his minister Josue: and Moses going up into the mount of God, Said to the ancients: Wait ye here till we return to you. You have Aaron and Hur with you: if any question shall arise, you shall refer it to them.
And when Moses was gone up, a cloud covered the mount. And the glory of the Lord dwelt upon Sinai, covering it with a cloud six days: and the seventh day he called him out of the midst of the cloud. And the sight of the glory of the Lord was like a burning fire upon the top of the mount, in the eyes of the children of Israel. And Moses, entering into the midst of the cloud, went up into the mountain: and he was there forty days, and forty nights.
- Source: Douay-Rheims 1899 American Edition of the Bible (in the public domain)