And the people murmured against Moses. As they had already done on the western shores of the Red Sea (Exodus 14:11, Exodus 14:12), and as they were about to do so often before their wanderings were over. (See below, Exodus 16:2; Exodus 17:3; Numbers 14:2; Numbers 16:41; Deuteronomy 1:27, etc.) "Murmuring" was the common mode in which they vented their spleen, when anything went ill with them; and as Moses had persuaded them to quit Egypt, the murmuring was chiefly against him. The men who serve a nation best are during their lifetime least appreciated. What shall we drink? Few disappointments are harder to bear than that of the man, who after long hours of thirst thinks that he has obtained wherewith to quench his intolerable longing, and on raising the cup to his lips, finds the draught so nauseous that he cannot swallow it. Very unpalatable water is swallowed when the thirst is great. But there is a limit beyond which nature will not go. There "may be water, water everywhere, yet not a drop to drink."
The Lord shewed him a tree.—Several trees or plants belonging to different parts of the world, are said to possess the quality of rendering bitter water sweet and agreeable; as the nellimaram of Coromandel, the sassafras of Florida, the yerva Caniani of Peru, and the perru nelli (Phylanthus emblica) of India. But none of them is found in the Sinaitic. peninsula. Burckhardt suggested that the berries of the ghurkud (Peganum retusum), a low thorny shrub which grows abundantly round the Ain Howarah, may have been used by Moses to sweeten the drink; but there are three objections to this.
1. Moses is not said to have used the berries, but the entire plant;
2. The berries would not have been procurable in April, since they do not ripen till June; and
3. They would not have produced any such effect on the water as Burckhardt imagined. In fact there is no tree or shrub now growing in the Sinaitic peninsula, which would have any sensible effect on such water as that of Ain Howarah; and the Bedouins of the neighbourhood know of no means by which it can be made drinkable. Many of the Fathers believed that the "tree" had no natural effect, and was commanded to be thrown in merely to symbolise the purifying power of the Cross of Christ. But to moderns such a view appears to savour of mysticism. It is perhaps most probable that there was some tree or shrub in the vicinity of the bitter fountain in Moses' time which had a natural purifying and sweetening power, but that it has now become extinct. If this be the case, the miracle consisted in God's pointing out the tree to Moses, who had no previous knowledge of it. The waters were made sweet. Compare the miracle of Elisha (2 Kings 2:19-22). There he made for them a statute and an ordinance. See the next verse. God, it appears, after healing the water, and satisfying the physical thirst of his people, gave them an ordinance, which he connected by a promise with the miracle. If they would henceforth render strict obedience to all his commandments, then he would "heal" them as he had healed the water, would keep them free at once from physical and from moral evil, from the diseases of Egypt, and the diseases of their own hearts. And there he proved them. From the moment of their quitting Egypt to that of their entering Canaan, God was ever "proving" his people—trying them, that is—exercising their faith, and patience and obedience and power of self-denial, in order to fit them for the position which they were to occupy in Canaan. He had proved them at the Red Sea, when he let them be shut in between the water and the host of the Egyptians—he proved them now at Marah by a bitter disappointment—he proved them again at Meribah (Exodus 17:1-7); at Sinai (Exodus 20:20); at Taberah (Numbers 11:1-3); at Kibroth-hattaavah (Numbers 11:34); at Kadesh (Numbers 13:26-33), and elsewhere. For forty years he led them through the wilderness" to prove them, to know what was in their heart" (Deuteronomy 8:1-20.), to fit them for their glorious and conquering career in the land of promise All these diseases. See Deuteronomy 7:15; Deuteronomy 28:27. Kalisch correctly observes that, though the Egyptians had the character in antiquity of being among the healthiest and most robust of nations (Herod. 2.77), yet a certain small number of diseases have always raged among them with extreme severity He understands the present passage of the plagues, which, however, are certainly nowhere else called "diseases." There is no reason why the word should not be taken literally, as all take it in the passages of Deuteronomy above cited.