Isaiah 22:1

1. Valley of vision Jerusalem itself, the seat of prophecy, the residence of Isaiah and his school of disciples. It is called a “valley” because, though on hills, it is surrounded by hills higher than itself; and because on three sides valleys steeply sloping to the city run into one running to the Dead Sea eastward.

What aileth thee A question occasioned by revelry resounding from all the housetops in a time of real peril, and this, from a daring, defiant sense of security. The question is a rebuke. The housetops were flat, and used as places of resort.