Charles H. Spurgeon on Psalms 12:2

"They speak vanity every one with his neighbour: with flattering lips and with a double heart do they speak." The feigned zeal is just like a waterman, that looks one way and rows another way; for this man pretends one thing and intends another thing; as Jehu pretended the zeal of God's glory, but his aim was at his master's kingdom; and his zeal to God's service was but to bring him to the sceptre of the kingdom. So Demetrius professed great love unto Diana, but his drift was to maintain the honour of his profession; and so we have too many that make great show of holiness, and yet their hearts aim at other ends; but they may be sure, though they can deceive the world and destroy themselves, yet not God, who knoweth the secrets of all hearts. Gr. Williams, 1636.