They belch out; or, they pour forth, (to wit, words, for what else should come out of the mouth? even sharp and bitter words, as the next clause explains it,) abundantly and vehemently, as a fountain doth waters, as this word signifies. See Pro_15:28Jer_6:7.
Swords, i.e. words as keen and mischievous as swords, as Psa_55:21 57:4.
Who, say they, doth hear? David doth not hear us, either to discover, and so to prevent our plots; Or to punish us for them; and God either doth not hear or not regard what we say and do against David; and therefore we may speak and act what we think fit.