Yet I have left me seven thousand in Israel, all the knees which have not bowed unto Baal, and every mouth which hath not kissed him. Seven thousand in Israel - That is, many thousands; for seven is a number of perfection, as we have often seen: so, The barren has borne seven - has had a numerous off-spring; Gold seven times purified - purified till all the dross is perfectly separated from it. The court and multitudes of the people had gone after Baal; but perhaps the majority of the common people still worshipped in secret the God of their fathers.
Every mouth which hath not kissed him - Idolaters often kissed their hand in honor of their idols; and hence the origin of adoration - bringing the hand to the mouth after touching the idol, if it were within reach; and if not, kissing the right hand in token of respect and subjection. The word is compounded of ad, to, and os, oris, the mouth. Dextera manu deum contingentes, ori admovebant: "Touching the god with their right hand, they applied it to their mouth." So kissing the hand, and adoration, mean the same thing -
Thus Pliny,
Inter adorandum, dexteram ad osculum referimus, totum corpus circumagimus: Nat. Hist. lib. xxviii., cap. 2.--
"In the act of adoration we kiss the right hand, and turn about the whole body."
Cicero mentions a statue of Hercules, the chin and lips of which were considerably worn by the frequent kissing of his worshippers:
Ut rictus ejus, et mentum paulo sit attritius, quod in precibus et gratulationibus, non solum id venerari, sed etiam osculari solent. - Orat. in Verrem.
I have seen several instances of this, especially in the paintings of old saints: the lips and mouth of beautiful paintings literally worn away by the unmerciful osculations of devotees.