Jesus invented Twitter? Well, He was a master at throwing out brief, pithy sayings that were calculated to provoke and offend. But that put Him at the pointy end of a long line of prophets who trafficked in barbs, riddles and shocking object lessons. Instead of doling out rose water, these troublemakers went straight for the gasoline. Those who indulge in murder and adultery are often the first to insist upon table manners, which is why God sends a Jeremiah to smash the pottery or an Isaiah to preach naked in the street. King Solomon, who was also an accomplished tweeter, might tell us that there is a time to be polite and a time to give some obstinate official a poke in the eye. The truth wrapped in a riddle or a joke is irresistible. What looks like skylarking is sometimes the fowler's snare. This selection of airborne quips and eagle-eyed observations by Michael Bull will likely challenge, offend, anger and unsettle. But it will also edify and perhaps even amuse.