In Deuteronomy we read twice that Moses fasted for forty days and forty nights. The first precedes Moses receiving the two tablets of stone in­scribed with the law. Before Moses re­ceived the law of God for the second time he fasted again. Why did Moses fast twice, for so long? And why did God give the law twice, especially con­sidering the LORD knew that while they were waiting the people had decided to represent God with an idol? Moses brought the words of the covenant from on high, but Israel had already broken the covenant. Moses visualizes this when he breaks the two tablets be­fore their eyes.

But then there is the second fast­ing for forty days and nights. Why again? The law of God was broken; the anger of the LORD was kindled. Moses intercedes in prayer, but also in fasting. Moses pleads that for God's glory he may not destroy them, but instead remember his promise given to Abraham, Isaac, and Jacob.

Moses fasted twice for forty days and forty nights. And twice God gave the law to lead his people in the way of the covenant. The people had once broken the law and Moses seemed to have averted the wrath of God. But really?

In 1 Kings 19 we read about the prophet Elijah. He also is called to do the LORD'S work in the midst of the people, even while they break the law in their pursuit of idol worship.

Elijah flees, firmly discouraged, into the wilderness. At first he is ready to die because he has nothing to hope for anymore. Following this he is fed by an angel of the LORD, and then travels for forty days and forty nights until he reaches the mountain of God, the place where God revealed himself to Moses and a sinful people in all his glory. Again it is the LORD who continues to be the God of life for his people. He encourages and re-sends his prophet to lead that stub­born people. Elijah is different from Moses, but the people are the same in their sins.

Now there is one more time that a servant of God fasted for forty days and forty nights. In Matthew 4 the Lord Jesus is led by the Spirit into the wilderness to be tempted by the devil. And this takes place "after fast­ing forty days and forty nights" (Matt 4:2). There is much the same here as the previous times. The people of God are still a sinful people, and God con­tinues to show his goodness. But there is also a big difference. For what Moses and Elijah could not accomplish, the Lord Jesus did.

He starts in the wilderness, where God had revealed himself to Israel. But Jesus does not break God's law. He loves God above all and using his law stops the attempt of the tempter, which is to have him make an idol of himself. Moses and Elijah were appointed by God, and God also ap­pointed Jesus and declared about him before the first fast in the wilderness that he is the Son with whom God is well pleased. Close to the second wilderness experience, the one on Golgotha, God the Father again declares this about Jesus. It happens during the transfiguration on a high mountain, when Moses and Elijah appear and converse with Jesus. God then declares Jesus to be the pleasing Ser­vant – the Son of God – to whom all must listen.

The chief Prophet speaks with two key prophets of the Old Testament: Moses, the one from the beginning of Israel's time in the Promised Land; and Elijah, the one from the beginning of Israel's time of utter decline in the Promised Land. Both fasted forty days and nights; both did prophet's works. They taught a stubborn people that the law of God is good for life. But then we see Jesus, the pleasing Servant and Son of God, who at the first fast proph­esied the law of God to be good for life. And then in the presence of Moses and Elijah, Jesus is again declared to be pleasing to God, for he supersedes them as the only high priest.

Fasting forty days and forty nights is about as long as one can live without food and not die. It teaches that even though we should've died because of our sins, we live because of the One who was cut off from the land of the living when he experienced the wilderness to the full extent.