Amos 4:5

and offer a sacrifice of thanksgiving with leaven, Cf Leviticus 7:12, and proclaim and publish the free offerings, making a great show of their religious fervor; for this liketh you, this they delighted in doing, O ye children of Israel, saith the Lord God. The more zeal the hypocrites show in imitating the outward worship of the true believers, the more guilt they heap upon themselves in the sight of God, whose all-seeing eye penetrates their flimsy pretexts and causes Him to emphasize His threats of punishment.