Whose mouth speaketh vanity
Vain words, lies, flatteries, and deceit, ( Psalms 12:2 ) ; when they speak loftily of themselves, and contemptuously of others; when they deliver out threatenings against some, and make fair promises to others; it is all vanity, and comes to nothing; and their right hand [is] a right hand of falsehood;
their strength and power to perform what they boast of, threaten, or promise, is fallacious, is mere weakness, and cannot effect anything; or their treaties, contracts, and covenants, they enter into and sign with their right hand, are not kept by them; they act the treacherous and deceitful part. The Latin interpreter of the Arabic version renders it, "their oath is an oath of iniquity"; and Ben Balaam in Aben Ezra, and R. Adnim in Ben Melech, say the word so signifies in the Arabic language; and Schultens F13 has observed the same: but the word in that language signifies the right hand as well as an oath, and need not be restrained to that; it is better to take it in the large sense, as Cocceius F14 does; whether they lifted up the hand to pray, or to swear; or gave it to covenant with, to make contracts and agreements; or stretched it out to work with; it was a right hand of falsehood.
F13 Observat. Philolog. p. 195.
F14 Lexicon, col. 312.