They are disappointed because they were confident: the two lines are parallel, with little if any intensification. They most logically refers to all the caravans in verses 18 and 19. Disappointed translates a verb meaning “ashamed.” They are deceived because they were sure the stream beds would have water, and so they feel ashamed. Using the same word, Psalm 22.5 says “In thee they trusted and were not disappointed.” Because they were confident: they were certain, sure, convinced that they would find water.

They come thither: thither is an old English word meaning “to that place,” and so we can translate “when they got there,” “when they reached the place where they were going,” or “when they arrived there.” Confounded translates a word found also in Psalm 35.26 as “confusion.” It is rendered somewhat poetically by New Jerusalem Bible as “when they reach the place, they stand aghast,” which is stronger than New International Version, “They arrive there only to be disappointed.”

Verse 20 may have to be restructured in some languages to give a clear translation. The following points should be considered: (1) It may be necessary to shift the reason clause from line a to the beginning of the line. (2) It may be necessary to combine the result clauses from both halves of the verse. (3) It may be necessary to make clear that the reason for being disappointed is the failure to find water, as implied in verses 15-18. As an example we may translate “Because they were sure they would find water, they went there, but they were disappointed and confused” or “The caravans were certain they would find water, but when they reached the place, they were confused and disappointed.”

Quoted with permission from Reyburn, Wiliam. A Handbook on Job. (UBS Helps for Translators). New York: UBS, 1992. For this and other handbooks for translators see here .