Exo 15:22-25, 23 When they came to Marah, they could not drink the water of Marah because it was bitter; … 25 And he (Moses) cried to the LORD, and the LORD showed him a log, and he threw it into the water, and the water became sweet…
Israel for 400 years cried for deliverance and God sent Moses to deliver them, but the fervency of prayer they had in Egypt evaporated when they left. It was replaced with grumbling. God set a series of tests to build their faith but soon they forgot and settled for their old ways. In this episode, much needed water in the desert turned out to be bitter. As Israel grumbled as always, Moses took the issue to the Lord in prayer. As an answer to his prayer, God directed Moses to a tree, which he cast into the water and suddenly the water became sweet. Moses could have not figured this out unless he prayed and God showed the means by which He would heal the water.
God is to be acknowledged, not only in the creating of things useful for man, but in discovering their usefulness. This tree is typical of the cross of Christ, which sweetens the bitter waters of affliction to all the faithful, and enables them to rejoice in tribulation. How many of the bitter places of the earth have been sweetened by prayer? the records of eternity alone will disclose.