1 Kings 19:18 - Matthew Poole's English Annotations on the Holy Bible

I have left, or, I have reserved to myself; I have by my grace kept from the common contagion; therefore thou art mistaken to think that thou art left alone, or that the people are universally corrupted. Or, I will reserve, from the slaughters last mentioned, and from Jezebel's rage. Seven thousand; either definitely so many; or rather, indefinitely, for many thousands; the number of seven being oft used for a great number, as Leviticus 26:18 Psalms 12:6 Micah 5:5 Malachi 3:9 Luke 17:4. For it is altogether improbable that all the Israelites except seven thousand did worship Baal; except Baal be here synecdochically put for all their idols, and the calves among others. All the knees which have not bowed unto Baal, and every mouth which hath not kissed him, i.e. all those who have not worshipped Baal, nor professed reverence or subjection to him; which idolaters did to their idols, by bowing the knee, Romans 11:4; compare Romans 14:11 Philippians 2:10, and by kissing them, or by kissing their hand with their mouth before them, and in respect to them; of which mention is made both in Scripture, as Job 31:26,27 Ho 13:2; compare Psalms 2:12, and in Pliny, Apuleius, and other profane authors. And God chooseth these expressions here, to teach men that it is not sufficient to deny inward veneration of mind and heart to idols, unless they do also forbear all outward significations of worship or reverence to them; and that he will own none for his people that do otherwise.