Charles Spurgeon Commentary Isaiah 44:13-14

"The carpenter stretcheth out a line; he marketh it out with a pencil; he shapeth it with planes, and he marketh it out with the compasses, and shapeth it after the figure of a man, according to the beauty of a man, to dwell in a house. He heweth him down cedars, and taketh the holm-tree and the oak, and strengtheneth for himself one among the trees of the forest: he planteth a fir-tree, and the rain doth nourish it." — Isaiah 44:13-14 (ASV)

The carpenter stretches out his rule; he marks it out with a line; he fits it with planes, and he marks it out with the compass, and makes it after the figure of a man, according to the beauty of a man; that it may remain in the house. He hews him down cedars, and takes the cypress and the oak, which he strengthens for himself among the trees of the forest: he plants an ash, and the rain nourishes it.

They like some choice wood from which to make their gods. So we see that these idol gods grow in the woods first, and then, afterwards, they need a carpenter's rule, and line, and compass, and plane in order to shape them according to his taste, or the order of his customers.