John Calvin on Acts 28:5

5. Shaking off the viper. The shaking off of the viper is a token of a quiet mind. For we see how greatly fear doth trouble and weaken men; and yet you must not think that Paul was altogether void of fear. For faith doth not make us blockish, as brain-sick men do imagine, when they be out of danger. “In umbra et extra teli jacturam,” in the shade, and out of bowshot. But though faith doth not quite take away the feeling of evils, yet it doth temperate the same, lest the godly be more afraid than is meet; that they may always be bold and have a good hope. So though Paul understand that the viper was a noisome beast, yet did he trust to the promise which was made to him, and did not so fear her plaguy “Pestiferum,” pestiferous, deadly. biting, that it did trouble him; because he was even ready to die if need had been.