Exodus 16:1 And they took their journey from Elim, and all the congregation of the children of Israel came unto the wilderness of Sin, which is between Elim and Sinai, on the fifteenth day of the second month after their departing out of the land of Egypt. 2 And the whole congregation of the children of Israel murmured against Moses and Aaron in the wilderness.
[Patriarchs & Prophets pp 291>292] From the Red Sea the hosts of Israel again set forth on their journey, under the guidance of the pillar of cloud. The scene around them was most dreary—bare, desolate-looking mountains, barren plains, and the sea stretching far away, its shores strewn with the bodies of their enemies; yet they were full of joy in the consciousness of freedom, and every thought of discontent was hushed.
But for three days, as they journeyed, they could find no water. The supply which they had taken with them was exhausted. There was nothing to quench their burning thirst as they dragged wearily over the sun-burnt plains. Moses, who was familiar with this region, knew what the others did not, that at Marah, the nearest station where springs were to be found, the water was unfit for use. With intense anxiety he watched the guiding cloud. With a sinking heart he heard the glad shout. “Water! water!” echoed along the line. Men, women, and children in joyous haste crowded to the fountain, when, lo, a cry of anguish burst forth from the host—the water was bitter.
In their horror and despair they reproached Moses for having led them in such a way, not remembering that the divine presence in that mysterious cloud had been leading him as well as them. In his grief at their distress Moses did what they had forgotten to do; he cried earnestly to God for help. “And the Lord showed him a tree, which when he had cast into the waters, the waters were made sweet.” Here the promise was given to Israel through Moses, “If thou wilt diligently hearken to the voice of the Lord thy God, and wilt do that which is right in His sight, and wilt give ear to His commandments, and keep all His statutes, I will put none of these diseases upon thee, which I have brought upon the Egyptians: for I am the Lord that healeth thee.”
Psalms 103:2 Bless the Lord, O my soul, and forget not all his benefits: 3 Who forgiveth all thine iniquities; who healeth all thy diseases; 4 Who redeemeth thy life from destruction; who crowneth thee with lovingkindness and tender mercies; 5 Who satisfieth thy mouth with good things; so that thy youth is renewed like the eagle's.
May God add His blessing to the study of His word. "Good night" and God bless!