Psalms 12:2

They speak vanity every one with his neighbour: with flattering lips and with a double heart do they speak.

They speak vanity - i:e., falsehood: speech that holds out hopes doomed to disappointment: nothingness х shaaw' (H7723)].

Every one with his neighbour - with the very one to whom he is bound to be a friend, but whom he cheats with hollow assurances of friendship. This aggravates the offence, that it is against his neighbour. Paul (Ephesians 4:25) refers to this, "Putting away lying, speak every man truth with his neighbour, because we are members one of another."

With flattering lips - literally, 'with a lip of smoothnesses.'

And with a double heart literally an heart and an heart; ie with duplicity "A double minded man" And with a double heart - literally, an heart and an heart; i:e., with duplicity. "A double-minded man" х dipsuchos (G1374), James 1:8] is one who has faith on the surface, but underneath lies unbelief. So 1 Chronicles 12:33, 'Ungodly professors have two hearts, two lords, two ends, two ways' (Cocceius).