Adam Clarke on Job 27:18

He buildeth his house as a moth - With great skill, great pains, and great industry; but the structure, however skillful, shall be dissolved; and the materials, however costly, shall be brought to corruption. To its owner it shall be only a temporary habitation, like that which the moth makes in its larve or caterpillar state, during its change from a chrysalis to a winged insect.

As a booth that the keeper maketh - A shed which the watchman or keeper of a vineyard erects to cover him from the scorching sun, while watching the ripening grapes, that they may be preserved from depredation. Travellers in the East have observed that such booths or sheds are made of the lightest and most worthless materials; and after the harvest or vintage is in, they are quite neglected, and by the winter rains, etc., are soon dissolved and destroyed.