Genesis 7:8

Of clean beasts, and of beasts that [are] not clean, and of fowls, and of every thing that creepeth upon the earth,

Ver. 8. And of those that are not clean.] So a Doeg may set his foot as far within the sanctuary as a David: A "generation of vipers" may come to John's baptism, Mat 3:7 as well as better men. But as these beasts came unclean to the ark, and went thence as unclean; so do most men to the holy ordinances; which yet are the heavenly exchange betwixt God and his elect: they present duty, He confers mercy. "The just Lord is in the midst thereof; he will not do iniquity: … but the unjust knoweth no shame"; Zep 3:5 he that is "filthy," will "be filthy still". Rev 22:11