(Maʹrah) [Bitterness].

One of Israel’s early encampments in the Sinai Peninsula. It was named “Marah” because of the unpalatable water found there. (Ex 15:23; Nu 33:8) Although having only recently been delivered from the Egyptians at the Red Sea, the Israelites gave way to faithless murmuring when they were unable to drink the water at Marah. Thereafter, at Jehovah’s direction, Moses cast a tree into the water, and the water became sweet. The Bible does not specify the kind of tree, and so there is no basis for identifying it. Of course, Jehovah could have directed Moses to a particular variety having natural properties for sweetening the water. But there is no need to seek a scientific or natural explanation, as the healing of the water was doubtless miraculous.​—Ex 15:23-25; compare 2Ki 2:19-22; 4:38-41.

Jehovah used the circumstances at Marah to test the Israelites as to their faith in his ability to  care for them. Since bad water can cause disease (2Ki 2:19), the sweetening of the water illustrated Jehovah’s ability to preserve the Israelites from the maladies experienced by the Egyptians. The “regulation” Jehovah then taught the Israelites was: Obedience to him as their God would prevent their being afflicted by the maladies he put upon the Egyptians.​—Ex 15:25, 26.

Marah is usually identified with ʽEin Hawwara 80 km (50 mi) SSE of modern Suez, just a few miles inland from the Red Sea.