2 The burden against the Valley of Vision. What ails you now, that you have all gone up to the housetops,
Isaiah 22:1
ESV - 1 The oracle concerning the valley of vision. What do you mean that you have gone up, all of you, to the housetops.
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I believe it is symbolic; it's a symbolic name generally understood to signify Jerusalem as being the home of prophetic vision (Isaiah 22:1,5).