tub-thumping

These day he engages the political world with tub-thumping opinion columns in the Spanish daily El Pais.

"I didn't ask you here to listen to me tub-thumping," George began apologetically, when we were alone.

His profession is termed the cloth (this item of Slang has been already referred to), and his practice is called tub-thumping.

"He does not waste his breath in tub-thumping," said one, looking reverently at the sealed figure.

Here was no tub-thumping soothsayer, but an inspired zealot.