12 Then Jethro, Moses' father-in-law, brought a burnt offering and other sacrifices to God, and Aaron came with all the elders of Israel to eat a meal with Moses' father-in-law in the presence of God.
4 Moses then wrote down everything the Lord had said. He got up early the next morning and built an altar at the foot of the mountain and set up twelve stone pillars representing the twelve tribes of Israel.
(Read Exodus 24:1-8)
A solemn covenant was made between God and Israel. Very solemn it was, typifying the covenant of grace between God and believers, through Christ. As soon as God separated to himself a peculiar people, he governed them by a written word, as he has done ever since. God's covenants and commands are so just in themselves, and so much for our good, that the more we think of them, and the more plainly and fully they are set before us, the more reason we may see to comply with them. The blood of the sacrifice was sprinkled on the altar, on the book, and on the people. Neither their persons, their moral obedience, nor religious services, would meet with acceptance from a holy God, except through the shedding and sprinkling' of blood. Also the blessings granted unto them were all of mercy; and the Lord would deal with them in kindness. Thus the sinner, by faith in the blood of Christ, renders willing and acceptable obedience.
Matthew Henry's Commentary on Exodus 18:12
Commentary on Exodus 18:7-12
(Read Exodus 18:7-12)
Conversation concerning God's wondrous works is good, and edifies. Jethro not only rejoiced in the honour done to his son-in-law, but in all the goodness done to Israel. Standers-by were more affected with the favours God had showed to Israel, than many were who received them. Jethro gave the glory to Israel's God. Whatever we have the joy of, God must have the praise. They joined in a sacrifice of thanksgiving. Mutual friendship is sanctified by joint worship. It is very good for relations and friends to join in the spiritual sacrifice of prayer and praise, as those that meet in Christ. This was a temperate feast; they did eat bread, manna. Jethro must see and taste that bread from heaven, and though a gentile, is welcome: the gentiles are welcomed to Christ the Bread of life.