Isaiah 41:7

So the carpenter, the craftsman in wood and metal, encouraged the goldsmith, the man who cast the idols, and he that smootheth with the hammer him that smote the anvil, saying, It is ready for the soldering, saying of the soldered mass, It is good; and he fastened it with nails that it should not be moved. Although the picture, as put together, seems solid enough, yet the workmen, for safety's sake, put in a few nails to hold it upright, a fine bit of irony characterizing the vanity of idolatry and the helplessness of the idol worshipers, who trust in the work of man's hands.