adder's poison is under their lips; which may signify the malignity of sin in wicked men, which comes from the old serpent the devil; is latent in men; very infectious, like poison, and deadly and incurable, but by the grace of God, and blood of Christ: and may describe particularly the mischief of the tongue, which is a little member, as the asp is a little creature; but very mischievous, full of deadly poison, which lurks in it, lies under it, and which spitting out, it stupifies and kills insensibly; as do the calumnies of wicked men, and the doctrines of false teachers; see Ro 3:13.
The Targum is,"the poison of the spider;''though it is said the spider is not venomous.Selah; on this word, See Gill on "Ps 3:2". Hist. Animal. l. 2. c. 17. Philosoph. Transact. abridged, vol. 2. p. 800.
& vol. 5. par. 1. p.