Like a deceitful bow. — Religious observance has the appearance of a bow with the arrow on the string, apparently aimed at some object, but the string being slack, the aim is diverted.
The “raving insolence of their tongue” may mean the boasts that were made of the friendship of King Shebaka of Egypt, who made Israel his tool. In the land of Egypt they would thus become objects of derision. (Comp. Isaiah’s warning to his countrymen, Isaiah 30:1-8.)