When he should have swollen - When they expected that he would have swollen from the bite of the viper. The poison of the viper is rapid, and they expected that he would die soon. The word rendered “swollen” πίμπρασθαι pimprasthai means properly “to burn; to be inflamed,” and then “to be swollen from inflammation.” This was what they expected here, that the poison would produce a violent inflammation.
Or fallen down dead suddenly - As is sometimes the case from the bite of the serpent when a vital part is affected.
They changed their minds - They saw that he was uninjured, and miraculously preserved; and they supposed that none but a god could be thus kept from death.
That he was a god - That the Maltese were idolaters there can be no doubt; but what gods they worshipped is unknown, and conjecture would be useless. It was natural that they should attribute such a preservation to the presence of a divinity. A similar instance occurred at Lystra. See the notes on Acts 14:11.