They are illustrations of this true proverb: ¹  “A dog returns to its own vomit,” ²  and “A sow, after washing herself, ³  wallows in the mire.” ⁴ 

But, according to his promise, we are waiting for ¹  new heavens and a new earth, in which ²  righteousness truly resides. ³ 

And in their greed they will exploit you with deceptive words. Their ¹  condemnation pronounced long ago ²  is not sitting idly by; ³  their ⁴  destruction is not asleep.