not to lift a finger / not to do a [tap/hand's turn]
Contexto
After that fevered night Lennan went to his studio at the usual hour and naturally did not do a stroke of work. He was even obliged to send away his model. The fellow had been his hairdresser, but, getting ill, and falling on dark days, one morning had come to the studio, to ask with manifest shame if his head were any good.