Their poison [is] like the poison of a serpent
Either their "wrath" and fury, as the word F24 may be rendered, against God, his people, and even one another, is like that of a serpent when irritated and provoked; or their mischievous and devouring words are like the poison of asps under their lips, ( Romans 3:13 ) ; or the malignity of sin in them is here meant, which, like the poison of a serpent, is latent, hid, and lurking in them; is very infectious to all the powers and faculties of the soul, and members of the body; and is deadly and incurable, without the grace of God and blood of Christ;
[they are] like the deaf adder [that] stoppeth her ear;
the adder is a kind of serpent, in Hebrew called "pethen"; hence the serpent "Python". This is not, deaf naturally, otherwise it would have no need to stop its ear, but of choice; and naturalists F25 observe, that it is quicker of hearing than of sight. Jarchi indeed says, when it grows old it becomes deaf in one of its ears, and it stops its other ear with dust, that it may not hear the voice of the charmer; though others say F26 it stops one ear with its tail, and lays the other to the ground; but these seem fabulous. David speaks of it figuratively, that it acts as if it was deaf, regarding no enchantments, but bites notwithstanding; these having no influence on it, which, if they had any, could not be hindered by its deafness; and he compares wicked men to it, who are wilfully deaf to all good counsel and advice given them F1.
F24 (tmx) (yumov) , Sept. "furor", V. L.
F25 Plin. Nat. Hist. l. 8. c. 23.
F26 Isidor. Hispal. Origin. l. 12. c. 4.
F1 Vid. Gataker. Adversaria, c. 8. p. 70