2 Peter 2:22

20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.

21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.

But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
Of them the proverbs are true: “A dog returns to its vomit,” and, “A sow that is washed goes back to her wallowing in the mud.”
KJV
But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
WEB
But it has happened to them according to the true proverb, “The dog turns to his own vomit again,” and “the sow that has washed to wallowing in the mire.”
ASV
It has happened unto them according to the true proverb, The dog turning to his own vomit again, and the sow that had washed to wallowing in the mire.
DARBY
But that [word] of the true proverb has happened to them: [The] dog [has] turned back to his own vomit; and, [The] washed sow to [her] rolling in mud.
BLB
The thing of the true proverb has happened to them: “A dog having returned to [its] own vomit,” and, “A sow, having washed, to [her] rolling place in the mire.”
ÅB
Det er gått dem som det sanne ordtaket sier: «Hunden vender tilbake til sitt eget spy, og den nybadete grisen velter seg i gjørmen.»
OTB
Dette vises av det sanne ordtaket:
"En hund vender tilbake til sitt eget spy,"
og,
"En purke, etter å ha blitt vasket, vender tilbake til å velte seg i sølen."
B1930
Det er gått dem som det sanne ordsprog sier: Hunden vender sig om til sitt eget spy, og den vaskede so velter sig i søle.

Study notes (Tyndale)

Original text and word study

Cross references