is the rendering of the Hebrew sharab', שָׁרָב, in Isaiah 35:7. This word properly means "heat of the sun," as the A.V. renders it in Isaiah 49:10. Hence it is used to designate a phenomenon which is frequent in Arabia and Egypt, and may be occasionally seen in the southern parts of Europe; called by the Arabs Serab, and by the French Le Mirage, by which name it is also commonly known in English. Descriptions of this illusion are often given by travelers. It consists in the appearance of a lake or sea in the midst of a plain where none in reality exists. It is produced by the reflection of the rays of light from strata of air heated by the sand or the sun; and it frequently exhibits, along with the undulating appearance of water, the shadows of objects within or around the plain, both in a natural and in an inverted position. The deception is most complete, and to the weary traveler who is attracted by it, it is in the highest degree mortifying, since, instead of refreshing water, he finds himself in the midst of nothing but glowing sand. It is often used proverbially. or for the sake of comparison, by the Arabs, as in the Koran (Sur. 24:39): "But as for those who believe not, their works are like the serab of the plain: the thirsty imagines it to be water, but when he reaches it he finds it is nothing." The same figure occurs in Isaiah 35:7 : "The sharab shall become a lake," i.e. the illusive appearance of a lake in the desert shall become a real lake of refreshing waters. See Gesenius and Henderson on Isaiah, and comp. the descriptions and explanations in Kitto's Physical History of Palestine, p. 147, 150, 151. (See MIRAGE).