Albert Barnes Commentary Acts 28:6

"But they expected that he would have swollen, or fallen down dead suddenly: but when they were long in expectation and beheld nothing amiss came to him, they changed their minds, and said that he was a god." — Acts 28:6 (ASV)

When he should have swollen. When they expected 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"—pimprasyai—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 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 Acts 14:11.

The word "Howbeit" means "However." The term "looked" signifies "expected." For the declaration that he was a god, compare Acts 14:11.